Radar Outage Notification 13:09:59.4692501

NOUS63 KLOT 301909
FTMLOT
Message Date: Nov 30 2011 19:09:27KLOT Dual Pol radar is back online.

Test Message 11:00:11.3921488

THIS IS THE WEEKLY TEST OF THE WXWARN1 ALERT SYSTEM THIS IS ONLY A TEST

Radar Outage Notification 09:03:15.3226904

NOUS63 KLOT 301501
FTMLOT
Message Date: Nov 30 2011 15:01:43KLOT dual pol radar is go offline several hours for preventive maintenance checks.

Radar Outage Notification 16:38:05.5928615

NOUS63 KLOT 282235
FTMLOT
Message Date: Nov 28 2011 22:35:15KLOT radar is back online.

Radar Outage Notification 11:08:18.3969701

NOUS63 KLOT 281705
FTMLOT
Message Date: Nov 28 2011 17:05:11KLOT radar will be down several hours for maintenance Calibration checks. M9

Test Message 11:00:56.3925944

THIS IS THE WEEKLY TEST OF THE WXWARN1 ALERT SYSTEM THIS IS ONLY A TEST

Flood Potential Outlook 13:36:49.4851891

...ADVANCED HYDROLOGIC PREDICTION SERVICE...AHPS...ENABLES
THE NATIONAL WEATHER SERVICE...NWS...TO PROVIDE LONG-RANGE
PROBABILISTIC RIVER OUTLOOKS...

THE VALUES IN THE TABLE BELOW ARE VALID 11/28/2011 - 2/26/2012
IN THE TABLE BELOW...THE 90 THROUGH 10 PERCENT COLUMNS INDICATE
THE CHANCE THAT A LOCATION ON A RIVER COULD RISE ABOVE THE LISTED
STAGE LEVELS IN THE NEXT 90 DAYS.

FOR EXAMPLE: THE KANKAKEE RIVER AT DUNNS BRIDGE HAS A FLOOD STAGE OF
10 FEET. WITHIN THE NEXT 90 DAYS...THERE IS A 60 PERCENT CHANCE
THE RIVER WILL RISE ABOVE 8.5 FT.

LOCATION FS (FT) 90% 80% 70% 60% 50% 40% 30% 20% 10%
-------- ------- --- --- --- --- --- --- --- --- ---
KANKAKEE RIVER
DUNNS BRIDGE 10.0 7.0 7.3 8.0 8.5 9.0 9.3 10.2 11.2 11.7
KOUTS 11.0 8.2 8.4 9.1 9.6 10.1 10.4 11.3 12.3 12.8
SHELBY 9.0 7.8 8.2 8.9 9.4 9.9 10.5 11.4 12.6 13.1
MOMENCE 5.0 2.9 3.1 3.4 3.6 4.0 4.3 5.1 5.3 6.0
WILMINGTON 6.5 2.0 2.4 2.6 3.1 3.9 4.8 5.4 5.8 6.1

SUGAR CREEK
MILFORD 18.0 5.2 7.3 9.7 11.6 12.4 16.0 17.7 18.3 19.8

IROQUOIS RIVER
RENSSELAER 12.0 7.0 8.1 8.6 9.2 10.2 11.2 12.1 13.3 14.6
FORESMAN 18.0 10.9 12.0 12.8 13.8 14.6 16.1 17.1 18.0 19.1
IROQUOIS 18.0 9.7 11.6 12.8 14.6 15.7 17.7 19.3 20.4 22.3
CHEBANSE 16.0 4.5 5.7 6.6 7.3 8.3 10.0 11.7 13.7 15.1

DES PLAINES RIVER
RUSSELL 7.0 4.0 4.9 6.0 6.5 6.9 7.0 7.1 7.3 7.6
GURNEE 7.0 2.7 3.4 4.3 4.8 5.3 5.6 6.0 6.6 7.5
DES PLAINES 5.0 1.3 1.5 1.8 2.1 2.2 2.6 3.1 3.7 4.0
LINCOLNSHIRE 12.5 7.5 8.1 9.0 9.5 10.0 10.2 10.8 11.1 12.1
RIVERSIDE 7.0 4.1 4.6 5.0 5.5 6.0 6.5 6.9 7.2 8.2

FOX RIVER
MONTGOMERY 13.0 11.8 12.0 12.4 12.5 12.7 12.9 13.1 13.2 13.4
DAYTON 12.0 7.4 8.5 9.1 9.6 10.5 10.8 11.7 12.5 13.3

EAST BR DU PAGE RIVER
BOLINGBROOK 19.5 16.6 17.6 17.8 18.2 18.7 19.3 19.5 19.8 20.7

DU PAGE RIVER
SHOREWOOD 6.5 3.4 3.7 4.1 4.4 4.6 5.0 5.4 5.7 6.2

MAZON RIVER
COAL CITY 12.0 2.2 2.6 3.3 3.8 4.8 5.6 6.8 7.1 8.6

VERMILION RIVER
PONTIAC 14.0 4.0 4.7 5.1 5.6 6.4 7.5 9.5 10.3 12.6
LEONORE 16.0 5.1 6.8 7.2 8.2 10.4 12.3 13.8 14.8 17.9

THORN CREEK
THORNTON 10.0 4.0 4.8 5.3 5.7 6.4 7.3 8.7 9.8 10.9

HART DITCH
DYER 12.0 3.7 4.0 4.3 4.6 5.0 5.6 6.2 6.9 7.5

LITTLE CALUMET RIVER
MUNSTER 12.0 8.7 9.0 9.3 10.1 11.0 11.6 12.3 13.0 14.3
SOUTH HOLLAND 16.5 8.6 9.6 9.9 10.5 11.2 12.1 13.1 14.1 14.7

ILLINOIS RIVER
MORRIS 16.0 6.2 7.1 8.2 9.3 10.1 13.2 14.7 16.3 19.3
OTTAWA 463.0

LA SALLE 20.0 12.8 13.8 14.8 16.8 19.0 21.8 22.8 24.0 25.5

KISHWAUKEE RIVER
BELVIDERE 9.0 2.8 3.5 4.0 4.5 5.4 5.9 6.5 7.4 8.6
PERRYVILLE 12.0 7.1 8.0 8.9 9.5 10.1 10.8 11.4 12.5 13.6

SOUTH BRANCH KISHWAUKEE RIVER
DE KALB 10.0 3.5 3.9 4.8 5.1 5.6 6.1 6.7 7.3 8.3

ROCK RIVER
ROCKTON 10.0 3.8 4.1 4.8 5.3 5.8 6.1 6.5 7.5 8.3
LATHAM PARK 10.0 4.6 4.8 5.3 5.7 6.1 6.3 6.7 7.5 8.0
ROCKFORD 9.0 2.8 2.9 3.1 3.1 3.2 3.2 3.3 3.5 3.6
BYRON 13.0 6.4 6.9 8.0 8.5 9.0 9.4 9.8 10.6 11.2

PECATONICA RIVER
SHIRLAND 12.0 5.8 6.4 7.2 8.3 8.6 9.5 9.8 10.9 12.1

THE NATIONAL WEATHER SERVICE CHICAGO OFFICE IN ROMEOVILLE ISSUES LONG
RANGE AHPS OUTLOOKS FOR ALL RIVER FORECAST LOCATIONS. THIS PRODUCT IS
UPDATED MONTHLY AROUND MID-MONTH. THESE OUTLOOKS ARE ISSUED IN
ADDITION TO THE 5 DAY RIVER FORECASTS THAT ARE ISSUED WHEN RIVER
FORECAST LOCATIONS ARE IN FLOOD OR FORECAST TO RISE ABOVE FLOOD
STAGE.

THIS LONG-RANGE PROBABILISTIC OUTLOOK CONTAINS FORECAST VALUES THAT
ARE CALCULATED USING MULTIPLE SEASON SCENARIOS FROM 30 OR MORE YEARS
OF CLIMATOLOGICAL DATA INCLUDING CURRENT CONDITIONS OF THE RIVER...
SOIL MOISTURE...AND 30 TO 90 DAY LONG-RANGE OUTLOOKS OF TEMPERATURE
AND PRECIPITATION.

BY PROVIDING THE COMPLETE RANGE OF PROBABILISTIC NUMBERS...THE LEVEL
OF RISK ASSOCIATED WITH LONG-RANGE PLANNING DECISIONS CAN BE
DETERMINED. THESE PROBABILISTIC FORECASTS ARE PART OF THE NATIONAL
WEATHER SERVICE ADVANCED HYDROLOGIC PREDICTION SERVICE.

VISIT OUR WEB PAGE AT WEATHER.GOV/CHICAGO FOR MORE WEATHER AND RIVER
INFORMATION INCLUDING GRAPHS OF PROBABILISTIC RIVER OUTLOOKS.

Non-Precipitation Watch, Warning, Advisory 17:00:52.6063948

...WIND ADVISORY IS CANCELLED...

THE NATIONAL WEATHER SERVICE IN CHICAGO HAS CANCELLED THE WIND
ADVISORY.

WINDS HAVE ABATED BELOW CRITERIA WITH SUNSET THIS
EVENING...THEREFORE THE WIND ADVISORY HAS ENDED.

Non-Precipitation Watch, Warning, Advisory 15:08:03.5393817

...WIND ADVISORY REMAINS IN EFFECT UNTIL 6 PM CST /7 PM EST/ THIS
EVENING...

A WIND ADVISORY REMAINS IN EFFECT UNTIL 6 PM CST /7 PM EST/ THIS
EVENING.

* TIMING...STRONG WINDS WILL BEGIN TAPERING BACK BELOW WIND
ADVISORY CRITERIA EARLY THIS EVENING.

* WINDS...SUSTAINED WINDS OF 25 TO 35 MPH WITH OCCASIONAL GUSTS
TO 45 MPH ARE EXPECTED ACROSS NORTHERN ILLINOIS AND NORTHWEST
INDIANA.

* IMPACTS...GUSTY WINDS MAY CAUSE SMALL OBJECTS SUCH AS TRASH
BINS TO BLOW AROUND. STAY AWAY FROM HIGH OBJECTS OUTDOORS SUCH
AS TREES. GUSTY WINDS WILL ALSO MAKE TRAVEL HAZARDOUS...
ESPECIALLY FOR HIGH PROFILE VEHICLES.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

A WIND ADVISORY MEANS THAT SUSTAINED WINDS OF 30 TO 39 MPH...OR
GUSTS BETWEEN 45 AND 57 MPH...ARE LIKELY. WINDS THIS STRONG CAN
CAUSE MINOR PROPERTY DAMAGE UNLESS PRECAUTIONS ARE TAKEN. DRIVING
MAY BE DIFFICULT...ESPECIALLY IN HIGH PROFILE VEHICLES. MOTORISTS
SHOULD BE ALERT AND USE CAUTION.

&&

Radar Outage Notification 13:55:08.4960692

NOUS63 KLOT 181954
FTMLOT
Message Date: Nov 18 2011 19:54:58KLOT radar is back online.

Non-Precipitation Watch, Warning, Advisory 10:20:38.3686562

...WIND ADVISORY IN EFFECT UNTIL 6 PM CST /7 PM EST/ THIS
EVENING...

THE NATIONAL WEATHER SERVICE IN CHICAGO HAS ISSUED A WIND
ADVISORY...WHICH IS IN EFFECT UNTIL 6 PM CST...7 PM EST...THIS
EVENING.

* TIMING...WINDS WILL CONTINUE TO INCREASE THROUGH EARLY
AFTERNOON...BEFORE TAPERING BACK BELOW CRITERIA THIS EVENING.

* WINDS...SUSTAINED WINDS OF 30 MPH WITH GUSTS TO 45 MPH ARE
EXPECTED ACROSS NORTHERN ILLINOIS AND NORTHWEST INDIANA.

* IMPACTS...GUSTY WINDS MAY CAUSE SMALL OBJECTS SUCH AS TRASH BINS
TO BLOW AROUND. STAY AWAY FROM HIGH OBJECTS OUTDOORS SUCH AS
TREES. GUSTY WINDS WILL ALSO MAKE TRAVEL HAZARDOUS...ESPECIALLY
FOR HIGH PROFILE VEHICLES.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

A WIND ADVISORY MEANS THAT SUSTAINED WINDS OF 30 TO 39 MPH...OR
GUSTS BETWEEN 45 AND 57 MPH...ARE LIKELY. WINDS THIS STRONG CAN
CAUSE MINOR PROPERTY DAMAGE UNLESS PRECAUTIONS ARE TAKEN. DRIVING
MAY BE DIFFICULT...ESPECIALLY IN HIGH PROFILE VEHICLES. MOTORISTS
SHOULD BE ALERT AND USE CAUTION.

&&

Special Weather Statement 09:11:48.3277691

...STRONG WINDS EXPECTED ACROSS NORTHERN ILLINOIS AND NORTHWEST
INDIANA...

STRONG WINDS HAVE ALREADY DEVELOPED ACROSS THE REGION THIS MORNING
IN RESPONSE TO A BROAD AREA OF LOW PRESSURE OVER THE CENTRAL AND
NORTHERN PLAINS. WINDS WILL STEADILY INCREASE THROUGH THE
REMAINDER OF THIS MORNING INTO THIS AFTERNOON... WITH SPEEDS OF
20 TO 30 MPH AND GUSTS TO 40 MPH ACROSS THE ENTIRE OUTLOOK AREA.
LOCALIZED GUSTS IN EXCESS OF 40 MPH ARE POSSIBLE... AND MAY PROMPT
A WIND ADVISORY SHOULD THEY BECOME MORE WIDESPREAD THEN CURRENTLY
EXPECTED.

GUSTY WINDS MAY CAUSE SMALL OBJECTS SUCH AS TRASH BINS TO BLOW
AROUND. STAY AWAY FROM HIGH OBJECTS OUTDOORS SUCH AS TREES. GUSTY
WINDS WILL ALSO MAKE TRAVEL HAZARDOUS...ESPECIALLY FOR HIGH
PROFILE VEHICLES.

Radar Outage Notification 09:03:56.3230964

NOUS63 KLOT 181502
FTMLOT
Message Date: Nov 18 2011 15:02:41KLOT Dual Pol radar will be down for several hour for corrective maintenance repair. KCM

Radar Outage Notification 20:08:54.7180865

NOUS63 KLOT 180207
FTMLOT

MESSAGE DATE: NOV 18 2011 02:07:26

MDW TWR IS BACK ONLINE.

Radar Outage Notification 10:54:33.3888027

NOUS63 KLOT 171654
FTMLOT
Message Date: Nov 17 2011 16:54:26KLOT Dual Pol radar is going offline for RDA Software Update 12.1, RPG Software Update 12.3 and Security Scan.

Test Message 11:00:28.3923172

THIS IS THE WEEKLY TEST OF THE WXWARN1 ALERT SYSTEM THIS IS ONLY A TEST

Radar Outage Notification 13:53:45.4952475

NOUS63 KLOT 151953
FTMLOT
Message Date: Nov 15 2011 19:53:32KLOT Dual Pol radar is back online.

Radar Outage Notification 10:37:38.3787542

NOUS63 KLOT 151637
FTMLOT
Message Date: Nov 15 2011 16:37:18KLOT Dual Pol radar is going offline for PMI's. It will be back up in several hours.

Mesoscale Discussion 11:25:19.4070780

AREAS AFFECTED...E CNTRL IL INTO CNTRL INDIANA

CONCERNING...SEVERE POTENTIAL...TORNADO WATCH LIKELY

VALID 141724Z - 141900Z

STORMS ARE EXPECTED TO INITIATE IN THE NEXT 1-2 HOURS AND A TORNADO
WATCH WILL LIKELY BE ISSUED BY 18Z.

SURFACE ANALYSIS SHOWS A LOW CENTERED OVER CNTRL IL...WITH A WARM
FRONT EXTENDING EWD ACROSS NRN INDIANA AND INTO NWRN OH. PRESSURE
FALLS HAVE ACCELERATED ALONG THE N OF THE WARM FRONT...WHICH IS
GRADUALLY SHIFTING NWD WITH LOW 60S DEWPOINTS NOW EXTENDING N OF
IND.

VISIBLE SATELLITE IMAGERY SHOWS BOUNDARY LAYER CU FIELDS NOW
INCREASING NEAR THE LOW CENTER/WARM FRONT INTERSECTION...AND ALSO
BEGINNING TO DEVELOP A BIT SWWD ALONG THE DEVELOPING COLD FRONT.
OBJECTIVE ANALYSIS INDICATES THAT MOST OF THE CIN HAS ERODED AS
WELL. WITH CONTINUED FORCING AND POCKETS OF HEATING...STORMS SHOULD
INITIATE SOON OVER CNTRL AND E CNTRL IL...MOVING QUICKLY EWD CROSS
INDIANA AND INTO WRN OH LATER TODAY.

DEEP LAYER WIND FIELDS ARE VERY STRONG...AND EFFECTIVE SRH VALUES
ARE WELL IN EXCESS OF 300 M2/S2. WHILE SOME UPDRAFTS MAY STRUGGLE TO
REMAIN UPRIGHT INITIALLY...WITH TIME THEY ARE EXPECTED TO FORM INTO
MATURE SUPERCELLS CAPABLE OF TORNADOES AND DAMAGING WIND. A STORM OR
TWO MAY RIDE RIGHT ALONG THE WARM FRONT...WITH A CORRIDOR OF
PARTICULARLY DAMAGING WINDS AND/OR TORNADOES POSSIBLE THERE.

..JEWELL.. 11/14/2011

...PLEASE SEE WWW.SPC.NOAA.GOV FOR GRAPHIC PRODUCT...

ATTN...WFO...CLE...ILN...IWX...IND...PAH...LOT...ILX...LSX...

LAT...LON 38898904 39828912 40998837 41238687 41598438 41518376
40938348 40008399 39538461 39048568 38838631 38698734
38578833 38898904

Non-Precipitation Watch, Warning, Advisory 18:02:35.6430545

...WIND ADVISORY HAS EXPIRED...

THE WIND ADVISORY IS NO LONGER IN EFFECT.

Non-Precipitation Watch, Warning, Advisory 15:48:39.5634980

...WIND ADVISORY REMAINS IN EFFECT UNTIL 6 PM CST /7 PM EST/ THIS
EVENING...

A WIND ADVISORY REMAINS IN EFFECT UNTIL 6 PM CST /7 PM EST/ THIS
EVENING.

* WINDS...SOUTHWEST WINDS OF 25 TO 30 MPH WITH GUSTS TO AROUND 45
MPH.

* IMPACTS...WINDS THIS STRONG MAY CAUSE MINOR PROPERTY DAMAGE
AND MAKE TRAVEL HAZARDOUS...ESPECIALLY FOR HIGHER PROFILE
VEHICLES.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

A WIND ADVISORY MEANS THAT WINDS OF 35 MPH ARE EXPECTED. WINDS
THIS STRONG CAN MAKE DRIVING DIFFICULT...ESPECIALLY FOR HIGH
PROFILE VEHICLES. USE EXTRA CAUTION.

&&

Non-Precipitation Watch, Warning, Advisory 10:02:22.3578057

...WIND ADVISORY REMAINS IN EFFECT UNTIL 6 PM CST /7 PM EST/ THIS
EVENING...

A WIND ADVISORY REMAINS IN EFFECT UNTIL 6 PM CST /7 PM EST/ THIS
EVENING.

* WINDS...SOUTH WINDS OF 20 TO 35 MPH WILL BECOME SOUTHWESTERLY
THIS AFTERNOON AS A COLD FRONT PUSHES ACROSS THE AREA. THERE
WILL ALSO BE FREQUENT WIND GUSTS AROUND 50 MPH DURING THE
ADVISORY THIS AFTERNOON.

* IMPACTS...WINDS THIS STRONG MAY CAUSE MINOR PROPERTY DAMAGE
AND MAKE TRAVEL HAZARDOUS...ESPECIALLY FOR HIGHER PROFILE
VEHICLES.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

A WIND ADVISORY MEANS THAT WINDS OF 35 MPH ARE EXPECTED. WINDS
THIS STRONG CAN MAKE DRIVING DIFFICULT...ESPECIALLY FOR HIGH
PROFILE VEHICLES. USE EXTRA CAUTION.

&&

Non-Precipitation Watch, Warning, Advisory 03:54:55.1395404

...WIND ADVISORY REMAINS IN EFFECT FROM 8 AM CST /9 AM EST/ THIS
MORNING TO 6 PM CST /7 PM EST/ THIS EVENING...

A WIND ADVISORY REMAINS IN EFFECT FROM 8 AM CST /9 AM EST/ THIS
MORNING TO 6 PM CST /7 PM EST/ THIS EVENING.

* WINDS...AS A COLD FRONT PUSHES APPROACHES THE AREA EARLY THIS
AFTERNOON...WINDS WILL BECOME SOUTHWESTERLY AND INCREASE TO 25
TO 35 MPH WITH OCCASIONAL GUSTS TO 50 MPH.

* IMPACTS...WINDS THIS STRONG MAY CAUSE MINOR PROPERTY DAMAGE
AND MAKE TRAVEL HAZARDOUS...ESPECIALLY FOR HIGHER PROFILE
VEHICLES.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

A WIND ADVISORY MEANS THAT WINDS OF 35 MPH ARE EXPECTED. WINDS
THIS STRONG CAN MAKE DRIVING DIFFICULT...ESPECIALLY FOR HIGH
PROFILE VEHICLES. USE EXTRA CAUTION.

&&

Non-Precipitation Watch, Warning, Advisory 20:47:46.7411734

...WIND ADVISORY REMAINS IN EFFECT FROM 8 AM CST /9 AM EST/ TO
6 PM CST /7 PM EST/ SUNDAY...

A WIND ADVISORY REMAINS IN EFFECT FROM 8 AM CST /9 AM EST/ TO
6 PM CST /7 PM EST/ SUNDAY.

* WINDS...SOUTH WINDS 20 TO 30 MPH WILL CONTINUE OVERNIGHT INTO
SUNDAY MORNING AHEAD OF A COLD FRONT. HOWEVER...AS THE COLD
FRONT PUSHES ACROSS THE AREA EARLY SUNDAY AFTERNOON...WINDS WILL
BECOME SOUTHWESTERLY AND CONTINUE TO INCREASE TO 25 TO 35 MPH
WITH SOME GUSTS AROUND 50 MPH AT TIMES.

* IMPACTS...WINDS THIS STRONG MAY CAUSE MINOR PROPERTY DAMAGE
AND MAKE TRAVEL HAZARDOUS...ESPECIALLY FOR HIGHER PROFILE
VEHICLES.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

A WIND ADVISORY MEANS THAT WINDS OF 35 MPH ARE EXPECTED. WINDS
THIS STRONG CAN MAKE DRIVING DIFFICULT...ESPECIALLY FOR HIGH
PROFILE VEHICLES. USE EXTRA CAUTION.

&&

Hazardous Weather Outlook 16:17:27.5806052

THIS HAZARDOUS WEATHER OUTLOOK IS FOR NORTH CENTRAL ILLINOIS...
NORTHEAST ILLINOIS AND NORTHWEST INDIANA.

.DAY ONE...TONIGHT.

NO HAZARDOUS WEATHER IS EXPECTED AT THIS TIME.

.DAYS TWO THROUGH SEVEN...SUNDAY THROUGH FRIDAY.

SOUTHWEST WINDS OF 25 TO 35 MPH WITH GUSTS AROUND 50 MPH ARE
EXPECTED ON SUNDAY.

THERE IS A CHANCE OF THUNDERSTORMS SOUTH OF THE KANKAKEE RIVER
ON MONDAY.

.SPOTTER INFORMATION STATEMENT...

SPOTTER ACTIVATION WILL NOT BE NECESSARY THROUGH TONIGHT.

&&

COMPLETE FORECAST INFORMATION IS AVAILABLE ON THE NWS CHICAGO
WEBPAGE: WEATHER.GOV/CHICAGO

Non-Precipitation Watch, Warning, Advisory 16:08:29.5752791

...WIND ADVISORY IN EFFECT FROM 8 AM CST /9 AM EST/ TO 6 PM CST
/7 PM EST/ SUNDAY...

THE NATIONAL WEATHER SERVICE IN CHICAGO HAS ISSUED A WIND
ADVISORY...WHICH IS IN EFFECT FROM 8 AM CST /9 AM EST/ TO 6 PM
CST /7 PM EST/ SUNDAY.

* WINDS...SOUTH WINDS WILL INCREASE TO 20 TO 30 MPH ON SUNDAY
MORNING AHEAD OF A COLD FRONT. HOWEVER...AS THE COLD FRONT
PUSHES ACROSS THE AREA SUNDAY AFTERNOON...WINDS WILL BECOME
SOUTHWESTERLY AND CONTINUE TO INCREASE TO 25 TO 35 MPH WITH SOME
GUSTS AROUND 50 MPH AT TIMES.

* IMPACTS...WINDS THIS STRONG MAY CAUSE MINOR PROPERTY DAMAGE AND
MAKE TRAVEL HAZARDOUS...ESPECIALLY FOR HIGHER PROFILE VEHICLES.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

A WIND ADVISORY MEANS THAT WINDS OF 35 MPH ARE EXPECTED. WINDS
THIS STRONG CAN MAKE DRIVING DIFFICULT...ESPECIALLY FOR HIGH
PROFILE VEHICLES. USE EXTRA CAUTION.

&&

Zone Forecast 15:55:28.5675472

...WIND ADVISORY IN EFFECT FROM 8 AM TO 6 PM CST SUNDAY...

.TONIGHT...MOSTLY CLOUDY. LOWS IN THE UPPER 40S. SOUTH WINDS
10 TO 20 MPH.
.SUNDAY...WINDY. MOSTLY CLOUDY. SCATTERED SPRINKLES AND A SLIGHT
CHANCE OF LIGHT RAIN IN THE MORNING. HIGHS IN THE UPPER 50S.
SOUTHWEST WINDS 20 TO 30 MPH WITH GUSTS UP TO 45 MPH AT TIMES.
CHANCE OF MEASURABLE PRECIPITATION 20 PERCENT.
.SUNDAY NIGHT...PARTLY CLOUDY. BREEZY. LOWS IN THE UPPER 30S.
SOUTHWEST WINDS 15 TO 25 MPH WITH GUSTS UP TO 30 MPH AT TIMES
EARLY IN THE EVENING DECREASING TO 10 TO 15 MPH IN THE LATE
EVENING AND OVERNIGHT.
.MONDAY...PARTLY SUNNY WITH A 30 PERCENT CHANCE OF SHOWERS. HIGHS
IN THE MID 50S. SOUTHWEST WINDS AROUND 10 MPH.
.MONDAY NIGHT...PARTLY CLOUDY. LOWS IN THE MID 30S. SOUTHWEST
WINDS AROUND 10 MPH IN THE EVENING BECOMING LIGHT AND VARIABLE
AFTER MIDNIGHT.
.TUESDAY...PARTLY CLOUDY. HIGHS IN THE LOWER 50S.
.TUESDAY NIGHT...MOSTLY CLEAR. LOWS AROUND 30.
.WEDNESDAY...MOSTLY SUNNY. HIGHS IN THE UPPER 30S.
.WEDNESDAY NIGHT AND THURSDAY...MOSTLY CLEAR. LOWS IN THE MID
20S. HIGHS IN THE MID 40S.
.THURSDAY NIGHT AND FRIDAY...PARTLY CLOUDY. LOWS IN THE LOWER
30S. HIGHS AROUND 50.
.FRIDAY NIGHT...MOSTLY CLOUDY WITH A 30 PERCENT CHANCE OF
SHOWERS. LOWS AROUND 40.
.SATURDAY...MOSTLY CLOUDY WITH A 40 PERCENT CHANCE OF SHOWERS.
HIGHS AROUND 50.

Area Forecast Discussion 15:49:00.5637060

.DISCUSSION...
342 PM CST

THE MAIN ISSUES CONTINUE TO BE WITH THE WINDS...ESPECIALLY ON SUNDAY
AND PRECIPITATION CHANCES AND AMOUNTS ON MONDAY.

WATER VAPOR IMAGERY EARLY THIS AFTERNOON INDICATES A POTENT NORTHERN
STREAM SHORT WAVE DIGGING SOUTHEAST ACROSS THE NORTHERN ROCKIES.
ASSOCIATED WITH THIS DISTURBANCE IS A POTENT SURFACE LOW OF 990 MB
ACROSS THE JAMES RIVER VALLEY OF NORTH DAKOTA. AS A
CONSEQUENCE...SOUTHERLY WINDS HAVE INCREASED ACROSS THE CENTRAL
CONUS DOWN STREAM OF THIS LOW AND UPSTREAM OF HIGH PRESSURE ACROSS
THE SOUTHEASTERN STATES. AREA PROFILER INDICATE A STOUT 40+ LOW
LEVEL JET ALREADY DEVELOPING ACROSS THE MID MISSISSIPPI RIVER
VALLEY. THIS TREND WILL IN THE WINDS WILL CONTINUE TONIGHT INTO
SUNDAY AS THE SURFACE LOW DEEPENS INTO THE SUB 985MB RANGE AS IT
MOVES NORTHEASTWARD ACROSS WESTERN ONTARIO.

LOW LEVEL MOISTURE WILL BE ON THE INCREASE LATER TONIGHT INTO SUNDAY
MORNING AS THE LOW LEVEL JET CONTINUES TO TRANSPORT MOISTURE
NORTHWARD FROM THE GULF. MODEL BUFFER SOUNDINGS SUGGEST THAT AS
ISENTROPIC ASCENT INCREASES ACROSS THE AREA THAT A LOWER CLOUD DECK
WITH DEVELOP ACROSS THE AREA BY EARLY SUNDAY MORNING. THERE COULD
ALSO BE A FEW SHOWERS OR AREAS OF DRIZZLE DURING THE EARLY TO MIDDLE
PART OF THE DAY. HOWEVER...BY FAR THE MAIN CONCERNS WITH THIS SYSTEM
WILL BE THE WINDS. IT APPEARS THAT THE SURFACE WINDS WILL REMAIN
ELEVATED TONIGHT. I AM A LITTLE CONCERNED THAT THERE COULD BE SOME
GUSTY WINDS TONIGHT...IN SPITE OF THE UNFAVORABLE TIME OF DAY. IT
APPEARS THAT THERE WILL NOT BE MUCH OF A NOCTURNAL INVERSION...AND
WITH THE WINDS SCREAMING ABOVE THE SURFACE IT MAY NOT BE HARD TO GET
SOME OF THAT MOMENTUM TO THE SURFACE.

DURING THE DAY ON SUNDAY...AS MENTIONED ABOVE THERE WILL LIKELY BE
SOME LOWER CLOUDS AND AREAS OF DRIZZLE DURING THE MORNING. THERE WAS
SOME CONCERN THAT THIS COULD LIMIT OUR MIXING POTENTIAL AND HENCE
OUR OVERALL THREAT FOR GETTING ADVISORY CRITERIA WINDS. HOWEVER...I
AM STILL EXPECTING THAT AS THE FRONT APPROACHES THE AREA TOMORROW
AFTERNOON THAT A GOOD DRY PUNCH OF AIR WILL QUICKLY ERODE THIS DECK
OF CLOUDS AND ALLOW US TO MIX THE MUCH STRONGER WINDS ALOFT. IN
ADDITION TO THIS...IT APPEARS THAT NORTHERN ILLINOIS WILL EXPERIENCE
FAVORABLE ISALLOBARIC PRESSURE RISES OF 9 TO 10 MB/6HR WITH THE
SURFACE FRONTAL PASSAGE SUNDAY AFTERNOON. MODEL BUFFER SOUNDINGS
ALSO LOOK VERY FAVORABLE FOR WIND GUSTS OF 40+ KT WITH MEAN BOUNDARY
LAYER WINDS IN EXCESS OF 40 KT. WITH THIS IN MIND...I HAVE ISSUED A
WIND ADVISORY FOR SUNDAY FOR WINDS OF 25 TO 35 MPH WITH GUSTS TO 50
MPH. I INCLUDED ALL BUT MY 3 FAR NORTHWEST COUNTIES IN AND AROUND
THE ROCKFORD AREA. IT STILL APPEARS TO BE A WINDY DAY IN THESE
AREAS. HOWEVER...DUE TO SOME UNCERTAINTIES ON THE STRENGTH OF THE
WINDS ACROSS MY NORTHWEST...I HAVE LEFT THEM OUT OF THE ADVISORY AT
THIS TIME.

THE WINDS SHOULD QUICKLY ABATE BY SUNDAY EVENING AND THEN THE OTHER
CONCERN WILL BE THE THREAT FOR RAINFALL ON MONDAY. THE WEATHER
PATTERN WILL REMAIN ACTIVE EARLY NEXT WEEK AS ANOTHER SERIES OF MID
LEVEL DISTURBANCES RACES EASTWARD WITHIN THE FAST NORTHERN STREAM
FLOW. THIS SHOULD DRIVE A WEAK SURFACE WAVE NORTHEASTWARD ALONG A
SURFACE BOUNDARY ACROSS CENTRAL ILLINOIS AND NORTHWESTERN INDIANA ON
MONDAY. ALTHOUGH THERE IS STILL SOME DISAGREEMENTS ON THE
NORTHWESTERN EXTENT OF THIS RAINFALL EVENT...IT DOES APPEAR THAT THE
SOUTHEASTERN 1/2 TO 2/3RDS OF MY CWA WILL HAVE GOOD CHANCES OF
EXPERIENCING SOME RAINFALL FROM THIS SYSTEM AS GOOD LARGE SCALE
FORCING FOR ASCENT OCCURS ACROSS THE AREA. THERE COULD EVEN BE A FEW
THUNDERSTORMS ACROSS PORTIONS OF EAST CENTRAL ILLINOIS AND PORTIONS
OF NORTHWESTERN INDIANA...CLOSER TO THE WARM SECTOR.

THIS WAVE WILL QUICKLY EXIT THE AREA MONDAY NIGHT...ESSENTIALLY
PUSHING THE SURFACE FRONTAL ZONE AND MAIN FOCUS FOR ADDITIONAL
RAINFALL FARTHER SOUTH ACROSS PORTIONS OF THE OHIO VALLEY AND
LOWER MISSISSIPPI VALLEY. THEREFORE...AS THE SOUTHERN STREAM UPPER
LOW...CURRENTLY OFF THE SOUTHERN CALIFORNIA COAST...EJECTS
EASTWARD ACROSS THE SOUTHERN MISSISSIPPI VALLEY...IT APPEARS THE
MAIN HEAVY RAINFALL EVENT WILL REMAIN SOUTH OF MY CWA ON TUESDAY.

THE FOCUS FOR MY AREA ON TUESDAY AND WEDNESDAY WILL BE WITH REGARDS
TO ANOTHER STRONG SYSTEM MOVING ACROSS SOUTHERN CANADA AND THE UPPER
MISSISSIPPI VALLEY. THIS STORM LOOKS TO PUSH ANOTHER STRONG COLD
FRONT ACROSS THE AREA LATE TUESDAY AFTERNOON AND EVENING. BEHIND
THIS FRONT...IT APPEARS THAT SOME OF THE COLDEST AIR THUS FAR THIS
SEASON COULD MOVE ACROSS THE AREA FOR WEDNESDAY AS A 1030 MB HIGH
BUILDS IN ACROSS THE LOWER MISSOURI VALLEY. TEMPERATURES AT 850 MB
AROUND -10 DEGREES CELSIUS COULD MOVE ACROSS SOUTHERN WI AND
NORTHERN ILLINOIS BY WEDNESDAY AFTERNOON. THIS WOULD LIKELY KEEP
SURFACE TEMPERATURES IN THE 30S IN MOST AREAS ON WEDNESDAY.
THEREFORE...I LOWERED TEMPERATURES A FEW DEGREES DURING THIS PERIOD
TO MATCH THIS THINKING.

LATER NEXT WEEK INTO NEXT WEEKEND IT APPEARS TEMPERATURES WILL
REBOUND AS ANOTHER TROUGH DIGS ACROSS WESTERN NORTH AMERICA.
DOWNSTREAM UPPER LEVEL RIDGING ACROSS THE SOUTHEASTERN CONUS SHOULD
SETUP SOUTHWEST FLOW ALOFT ACROSS THE CENTRAL PORTION OF THE COUNTY.
THIS LOOKS TO SET THE STAGE FOR ANOTHER ACTIVE WEATHER PATTERN
ACROSS THE AREA WITH MORE DECENT CHANCES FOR RAIN AND SOME WIND.

KJB

&&

.AVIATION...

//ORD AND MDW CONCERNS...UPDATED 21Z...

* SOUTH WIND GUSTS OF UP TO 25 KTS BEFORE SUNSET...POSSIBLY GUSTS
AFTER SUNSET.

* SOUTHWEST WINDS UP TO 40 KTS BY SUNDAY AFTERNOON.

* LOW-LEVEL WIND SHEAR TONIGHT.

* LOW CLOUD LIKELIHOOD LATE TONIGHT INTO SUNDAY MORNING.

RC/MTF

//DISCUSSION...UPDATED 21Z...

WITH GOOD MIXING AND TIGHTENING PRESSURE GRADIENT...INCREASED
SUSTAINED WINDS TO 15 KT AND GUSTS TO UP TO 25 KT AT THE NE IL AND
NW IN TAF SITES. RFD HAS NOT SEEN GUSTS YET BUT EXPECT GUSTS IN 20
KT RANGE BEFORE SUNSET. 0200Z START TIME FOR LLWS STILL LOOKS
GOOD. REMOVED GUSTS MUCH OF OVERNIGHT DUE TO EXPECTATION THAT
INVERSION BELOW LLWS WILL BE STOUT ENOUGH TO PREVENT MIXING DOWN
OF GUSTS. HOWEVER...CONTINUING INCREASE IN PRESSURE GRADIENT MAKE
THIS AN UNCERTAIN FORECAST. NAM...RUC AND GFS MODEL SOUNDINGS SHOW
25 KT+ WINDS ONLY A FEW HUNDRED FEET ABOVE SURFACE...SO IT IS
POSSIBLE OCCASIONAL GUSTS MAY OCCUR OVERNIGHT AND SUSTAINED WINDS
MAY NEED TO BE REVISED UPWARDS A FEW KNOTS.

RC

18Z DISCUSSION...

LOW PRESSURE WILL CONTINUE TO DEEPEN AS IT EVOLVES EAST ALONG THE
INTERNATIONAL BORDER OF ND/MN INTO TONIGHT. THIS WILL LEAD TO A
TIGHTENING PRESSURE GRADIENT ACROSS THE TAF SITES TONIGHT AND KEEP
SUSTAINED WINDS UP...POTENTIALLY EVEN INCREASING SLIGHTLY.
OCCASIONAL GUSTS TO 20 TO 25 KTS ARE LIKELY. ALSO BECAUSE OF THE
LOW DEEPENING...A SOUTHWEST LOW-LEVEL JET WILL FOCUS ATOP THE
AREA WITHIN THE 1500 TO 3000 FT LAYER. SPEEDS AS HIGH AS 55-60 KTS
ARE POSSIBLE IN THIS LAYER OVERNIGHT...POTENTIALLY CREATING PLANE
SPACING ISSUES THROUGH LOW-LEVEL WIND SHEAR. THESE STRONG
SOUTHERLY WINDS JUST OFF THE SURFACE TONIGHT WILL STEER MOISTURE
BACK AND WITH THAT WILL COME THE LIKELIHOOD OF MVFR AND POSSIBLY
IFR CEILINGS. AT LEAST SOME SCATTERED MORNING CLOUDS ARE
EXPECTED...WITH BROKEN CEILINGS BECOMING MORE FAVORED THAN THE
LAST FORECAST. SCATTERED LIGHT SHOWERS AND AREAS OF DRIZZLE ARE
POSSIBLE...MOST FAVORED SOUTH OF THE TAF SITES. AS THE
AFOREMENTIONED LOW PRESSURE WRAPS DRY AIR IN FROM THE WEST...THE
CLOUDS SHOULD PUSH EAST BY AFTERNOON. WITH THAT DRY SURGE HOWEVER
WILL COME EVEN GUSTIER AND HIGHER IMPACT SOUTHWEST SURFACE
WINDS...POTENTIALLY UP TO 45 KTS.

//ORD AND MDW CONFIDENCE...UPDATED 21Z...

* HIGH CONFIDENCE IN SOUTH WIND GUSTS UP TO 25 KT PRIOR TO SUNSET.
LOW CONFIDENCE IN GUSTS AFTER SUNSET.

* HIGH CONFIDENCE IN SOUTHWEST GUSTS REACHING UP TO 40 KTS ON SUNDAY
AFTERNOON...WITH POTENTIAL FOR SOME OF THESE GUSTS ALREADY IN
THE MORNING.

* HIGH CONFIDENCE IN LLWS FORECAST...AT LEAST 45 KT SOUTHWEST
FLOW WITHIN THE 1500 TO 3000 FT LAYER TONIGHT.

* LOW CONFIDENCE IN MORNING LOW CLOUDS AT ORD WITH MEDIUM
CONFIDENCE AT MDW. HIGH CONFIDENCE THAT ANY CLOUDS WILL SCATTER
BY EARLY TO MID AFTERNOON.

RC/MTF

//OUTLOOK FOR ORD/MDW FOR 00Z MONDAY-12Z SATURDAY...UPDATED 12Z...

SUNDAY NIGHT...VFR. SLOWLY DIMINISHING WINDS.

MONDAY...CHANCE SHRA. MVFR CIGS POSSIBLE.

TUESDAY...VFR LIKELY. BREEZY WEST WINDS.

WEDNESDAY...VFR.

THURSDAY...VFR. SLIGHT CHANCE SHRA LATE.

FRIDAY...CHANCE SHRA AND MVFR CIGS.

MTF

&&

.MARINE...
217 PM CST

DEEPENING LOW PRESSURE MOVING ACROSS THE INTERNATIONAL BORDER OF
MN TONIGHT AND INTO WESTERN ONTARIO ON SUNDAY WILL HAVE A LARGE
INFLUENCE ON LAKE MICHIGAN. SMALL CRAFT ADVISORY CONDITIONS ARE
BEING SPORADICALLY OBSERVED ALREADY...WITH 25 KT GUSTS SEEN ON OR
NEAR THE ILLINOIS SHORE. SOUTHERLY WIND SPEEDS WILL ONLY BE ON THE
INCREASE INTO TONIGHT WITH GALE CONDITIONS EXPECTED TO DEVELOP
PRIOR TO MIDNIGHT INCLUDING IN THE NEAR SHORE AREAS. THE WIND
DIRECTION MAY VARY SOME BETWEEN SOUTH AND SOUTHWEST ALL THE WAY
THROUGH SUNDAY MORNING...BECOMING A MORE DEFINED SOUTHWEST BY
SUNDAY AFTERNOON. HIGHER END GALES TO 45 KTS ARE MOST LIKELY AFTER
MORNING CLOUDS SCOUR AND THE COLD FRONT PASSES...WHICH IS EXPECTED
DURING THE EARLY TO MID AFTERNOON ON SUNDAY. THE MOST FAVORED
PORTION OF THE LAKE TO SEE THESE IS THE SOUTHERN HALF. SOME OF
THESE HIGHER END GUSTS COULD BE SEEN IN THE NEAR SHORE ZONES AS
WELL...PRIMARILY FROM NORTHERLY ISLAND AROUND TO MICHIGAN CITY.
WHILE GALES WILL SLOWLY SUBSIDE LATER SUNDAY NIGHT...THE OVERALL
PROGRESSIVE PATTERN OF LOW PRESSURES WILL CONTINUE THROUGH EARLY
WEDNESDAY. THE NEXT ROUND OF GALES IS FAVORED ON TUESDAY NIGHT AS
LOW PRESSURE MOVES EAST NEAR OR OVER LAKE SUPERIOR DRIVING A WELL-
DEFINED COLD FRONT EAST ACROSS LAKE MICHIGAN. WESTERLY GALES TO 35
KTS AT THIS TIME ARE FAVORED OVER THE NORTHERN HALF OF THE LAKE.

MTF

&&

.LOT WATCHES/WARNINGS/ADVISORIES...
IL...WIND ADVISORY...ILZ005-ILZ006-ILZ010-ILZ011-ILZ012-ILZ013-ILZ014-
ILZ019-ILZ020-ILZ021-ILZ022-ILZ023-ILZ032-ILZ033-ILZ039...8
AM SUNDAY TO 6 PM SUNDAY.

IN...WIND ADVISORY...INZ001-INZ002-INZ010-INZ011-INZ019...8 AM SUNDAY
TO 6 PM SUNDAY.

LM...GALE WARNING...LMZ080-LMZ261-LMZ362-LMZ364-LMZ366-LMZ563-LMZ565-
LMZ567-LMZ669-LMZ671-LMZ673-LMZ675-LMZ740-LMZ741-LMZ742-
LMZ743-LMZ744-LMZ745-LMZ777-LMZ779-LMZ868-LMZ870-LMZ872-
LMZ874-LMZ876-LMZ878...9 PM SATURDAY TO 9 PM SUNDAY.

SMALL CRAFT ADVISORY...NEARSHORE WATERS
UNTIL 9 PM SATURDAY.

&&

$$

Area Forecast Discussion 15:30:15.5525685

.DISCUSSION...
309 AM CST

AN ACTIVE FEW DAYS LAY AHEAD WITH THE MAIN FORECAST CONCERNS
CENTERED AROUND WINDS AND PRECIP CHANCES. EARLY MORNING WATER VAPOR
IMAGERY SHOWS A CORRIDOR OF FAIRLY FLAT UPPER FLOW OVER THE EASTERN
HALF OF THE COUNTRY WITH SLIGHT UPPER RIDGING TRANSLATING EASTWARD
ACROSS THE NORTHERN PLAINS AND UPPER MISSISSIPPI RIVER VALLEY. TO
THE WEST...A SERIES OF SHORTWAVES ARE LINED UP WITH ONE DIGGING INTO
WESTERN MONTANA AND ANOTHER MOVING ALONG THE SOUTHEASTERN ALASKAN
COAST TOWARD FAR NORTHERN BRITISH COLUMBIA. ANOTHER UPPER TROUGH IS
CUT OFF FROM THIS NORTHERN STREAM OF FLOW JUST OFF THE CALIFORNIA
COAST AND WILL PLAY A ROLE IN PRECIP CHANCES FOR OUR AREA EARLY NEXT
WEEK. AT THE SURFACE...LOW PRESSURE WAS OBSERVED JUST NORTHEAST OF
LAKE SUPERIOR. ANOTHER SURFACE LOW IS DEVELOPING OVER SOUTHERN
SASKATCHEWAN/CENTRAL MONTANA AS A RESULT OF THE AFOREMENTIONED UPPER
SHORTWAVE WITH A SUBTLE WARM FRONT/TROUGH ANALYZED FROM THE LOW
ARCHING SOUTHEASTWARD ACROSS NORTHERN ILLINOIS AND INDIANA. THIS LOW
WILL BE KEY IN BRINGING INCREASING WINDS TO THE REGION TONIGHT AND
SUNDAY.

TODAY...AM EXPECTING A MILDER DAY TODAY WITH WARM ADVECTION ONGOING
EARLY THIS MORNING. SOUTH WINDS WILL INCREASE EARLY THIS AFTERNOON
AND BECOME SOMEWHAT GUSTY AS THE PRESSURE GRADIENT TIGHTENS WITH THE
SURFACE LOW DEEPENING OVER THE NORTHERN PLAINS. MIXING TO BETWEEN
950 AND 925 MB IS EXPECTED TODAY RESULTING IN GUSTS AROUND 20 KT AT
TIMES AND HIGHS IN THE MID 50S NORTH TO UPPER 50S SOUTH OF
INTERSTATE 88...WITH A FEW AREAS POSSIBLY REACHING 60 DEGREES MAINLY
SOUTH OF INTERSTATE 80 THANKS TO THE BREEZY SOUTH-SOUTHWEST WINDS.

TONIGHT THROUGH SUNDAY NIGHT...THE SURFACE LOW WILL MOVE FROM
EASTERN NORTH DAKOTA INTO WESTERN ONTARIO TONIGHT WHILE DEEPENING
INTO THE 980-985 MB RANGE. WINDS AND TEMPS WILL BE TRICKY AS THEY
WILL BE DICTATED BY THE DECOUPLING OF THE BOUNDARY LAYER THIS
EVENING. AM THINKING THAT DECOUPLING MAY OCCUR WITH SUNSET LATE THIS
AFTERNOON ALLOWING GUSTS TO DIMINISH BUT THE TIGHTENING PRESSURE
GRADIENT WILL KEEP SUSTAINED WIND SPEEDS UP. THIS WOULD LEAD TO
LITTLE DROP OFF IN TEMPS THIS EVENING. A WEAK UPPER WAVE LOOKS TO
LIFT NORTHEASTWARD ACROSS THE AREA THIS EVENING BRINGING MODEST MID
LEVEL COOL ADVECTION FOR A SHORT TIME AND MAY SERVE AS A CATALYST
FOR MIXING TO RE-DEVELOP LEADING TO A RETURN OF WIND GUSTS. THE
CONCERN IS THAT THE LOW LEVEL JET RAMPS UP SIGNIFICANTLY THIS
EVENING WITH FORECAST SOUNDINGS INDICATING 30+ KT WINDS STARTING
AROUND 600 FT AGL AND 40+ KT WINDS AT 1000 FT WITH A PEAK AT AROUND
60 KT UP AROUND 2500 FT. ITS NOT OUT OF THE QUESTION THAT 30 KT
GUSTS COULD OCCUR OVERNIGHT. ANOTHER WARM FRONT LOOKS TO QUICKLY
CROSS THE AREA EARLY SUNDAY MORNING WITH A LOW LEVEL THERMAL AXIS
CRESTING THE AREA. WINDS BECOME A BIGGER ISSUE SUNDAY AS MIXING
COMMENCES. THE LOW WILL BE LIFTING NORTHEASTWARD TOWARDS SOUTHERN
HUDSON BAY AND LIKELY BE SOMEWHERE AROUND 980 MB. PEAK LOW LEVEL
WINDS DO SUBSIDE BUT A DEEP LAYER OF 40-50 KT WINDS CONTINUES INTO
EARLY SUNDAY AFTERNOON. MIXING SUPPORTS GUSTS TO NEAR 40 KT DURING
THE DAY WITH POTENTIAL FOR A BRIEF PERIOD OF HIGHER GUSTS OF 45 KT
OR POSSIBLY HIGHER AS THE COLD FRONT PASSES AROUND MIDDAY. PRECIP
CHANCES ARE NOT IMPRESSIVE WITH DEEP LAYER MOISTURE LACKING SO WILL
CONTINUE WITH SLIGHT AND LOW CHANCE POPS BUT THESE MAY EVEN BE TOO
HIGH. WINDS WILL DIMINISH OVER LAND AREAS SUNDAY EVENING.

MONDAY THROUGH WEDNESDAY...THE COOL FRONTAL BOUNDARY WILL WEAKEN AND
WASH OUT TO THE SOUTH AND EAST OF THE AREA SUNDAY NIGHT INTO MONDAY
BUT STILL BE INTACT ENOUGH TO KEEP A BELT OF POOLED MOISTURE FROM
THE LOWER LAKES INTO CENTRAL ILLINOIS. THE ALASKAN UPPER WAVE WILL
DAMPEN BUT THE NORTHERN STREAM WILL BEGIN TO PHASE WITH THE
CALIFORNIA CUTOFF UPPER LOW. A LEAD SHORTWAVE WILL EJECT
NORTHEASTWARD FROM THE CENTRAL PLAINS AHEAD OF THE DEVELOPING
LONGWAVE TROUGH AXIS AND PUSH A WEAK SURFACE TROUGH ALONG THE OLD
FRONT/AREA OF POOLED MOISTURE MONDAY. THIS SHOULD PUSH THE MOISTURE
NORTHWARD AND BACK INTO MOST OF THE FORECAST AREA MONDAY MORNING.
THIS WILL SUPPORT INCREASED RAIN CHANCES...PRIMARILY ACROSS THE
SOUTHEAST TWO-THIRDS TO THREE-QUARTERS OF THE AREA MONDAY. THE
LARGER SCALE UPPER TROUGH WILL SWING ACROSS THE AREA AS IT AMPLIFIES
TUESDAY WITH ANOTHER SURFACE LOW MOVING FROM THE UPPER MISSISSIPPI
RIVER VALLEY INTO WESTERN ONTARIO. ANOTHER SHARP COLD FRONT WILL
CROSS THE AREA LATER TUESDAY AFTERNOON OR EARLY TUESDAY EVENING.
ANOTHER PERIOD OF GUSTY WINDS IS EXPECTED WITH THE STRONG COLD
ADVECTION AS H85 TEMPS FALL BACK TO THE -6 OR -8 C RANGE INTO
WEDNESDAY FROM THEIR ABOVE ZERO C READINGS PRIOR TO THAT.

THURSDAY AND FRIDAY...DRIER WEATHER WILL RETURN INTO THURSDAY AS
HIGH PRESSURE MOVES SOUTH OF THE AREA BUT THE UPPER FLOW PATTERN
WILL REMAIN ACTIVE JUST TO THE NORTH OF THE AREA. THEREFORE CANNOT
RULE OUT A WAVE MOVING CLOSE ENOUGH TO THE AREA TO KICK OFF SOME
SHOWERS ESPECIALLY AS WARM ADVECTION RETURNS THURSDAY NIGHT. THE
UPPER FLOW WILL TURN SOUTHWESTERLY SUGGESTING A RETURN TO MORE
ACTIVE WEATHER NEXT WEEKEND THOUGH WE SHOULD SEE AN UPSWING IN TEMPS
BY THAT TIME.

MDB

&&

.AVIATION...

//ORD AND MDW CONCERNS...UPDATED 21Z...

* SOUTH WIND GUSTS OF UP TO 25 KTS BEFORE SUNSET...POSSIBLY GUSTS
AFTER SUNSET.

* SOUTHWEST WINDS UP TO 40 KTS BY SUNDAY AFTERNOON.

* LOW-LEVEL WIND SHEAR TONIGHT.

* LOW CLOUD LIKELIHOOD LATE TONIGHT INTO SUNDAY MORNING.

RC/MTF

//DISCUSSION...UPDATED 21Z...

WITH GOOD MIXING AND TIGHTENING PRESSURE GRADIENT...INCREASED
SUSTAINED WINDS TO 15 KT AND GUSTS TO UP TO 25 KT AT THE NE IL AND
NW IN TAF SITES. RFD HAS NOT SEEN GUSTS YET BUT EXPECT GUSTS IN 20
KT RANGE BEFORE SUNSET. 0200Z START TIME FOR LLWS STILL LOOKS
GOOD. REMOVED GUSTS MUCH OF OVERNIGHT DUE TO EXPECTATION THAT
INVERSION BELOW LLWS WILL BE STOUT ENOUGH TO PREVENT MIXING DOWN
OF GUSTS. HOWEVER...CONTINUING INCREASE IN PRESSURE GRADIENT MAKE
THIS AN UNCERTAIN FORECAST. NAM...RUC AND GFS MODEL SOUNDINGS SHOW
25 KT+ WINDS ONLY A FEW HUNDRED FEET ABOVE SURFACE...SO IT IS
POSSIBLE OCCASIONAL GUSTS MAY OCCUR OVERNIGHT AND SUSTAINED WINDS
MAY NEED TO BE REVISED UPWARDS A FEW KNOTS.

RC

18Z DISCUSSION...

LOW PRESSURE WILL CONTINUE TO DEEPEN AS IT EVOLVES EAST ALONG THE
INTERNATIONAL BORDER OF ND/MN INTO TONIGHT. THIS WILL LEAD TO A
TIGHTENING PRESSURE GRADIENT ACROSS THE TAF SITES TONIGHT AND KEEP
SUSTAINED WINDS UP...POTENTIALLY EVEN INCREASING SLIGHTLY.
OCCASIONAL GUSTS TO 20 TO 25 KTS ARE LIKELY. ALSO BECAUSE OF THE
LOW DEEPENING...A SOUTHWEST LOW-LEVEL JET WILL FOCUS ATOP THE
AREA WITHIN THE 1500 TO 3000 FT LAYER. SPEEDS AS HIGH AS 55-60 KTS
ARE POSSIBLE IN THIS LAYER OVERNIGHT...POTENTIALLY CREATING PLANE
SPACING ISSUES THROUGH LOW-LEVEL WIND SHEAR. THESE STRONG
SOUTHERLY WINDS JUST OFF THE SURFACE TONIGHT WILL STEER MOISTURE
BACK AND WITH THAT WILL COME THE LIKELIHOOD OF MVFR AND POSSIBLY
IFR CEILINGS. AT LEAST SOME SCATTERED MORNING CLOUDS ARE
EXPECTED...WITH BROKEN CEILINGS BECOMING MORE FAVORED THAN THE
LAST FORECAST. SCATTERED LIGHT SHOWERS AND AREAS OF DRIZZLE ARE
POSSIBLE...MOST FAVORED SOUTH OF THE TAF SITES. AS THE
AFOREMENTIONED LOW PRESSURE WRAPS DRY AIR IN FROM THE WEST...THE
CLOUDS SHOULD PUSH EAST BY AFTERNOON. WITH THAT DRY SURGE HOWEVER
WILL COME EVEN GUSTIER AND HIGHER IMPACT SOUTHWEST SURFACE
WINDS...POTENTIALLY UP TO 45 KTS.

//ORD AND MDW CONFIDENCE...UPDATED 21Z...

* HIGH CONFIDENCE IN SOUTH WIND GUSTS UP TO 25 KT PRIOR TO SUNSET.
LOW CONFIDENCE IN GUSTS AFTER SUNSET.

* HIGH CONFIDENCE IN SOUTHWEST GUSTS REACHING UP TO 40 KTS ON SUNDAY
AFTERNOON...WITH POTENTIAL FOR SOME OF THESE GUSTS ALREADY IN
THE MORNING.

* HIGH CONFIDENCE IN LLWS FORECAST...AT LEAST 45 KT SOUTHWEST
FLOW WITHIN THE 1500 TO 3000 FT LAYER TONIGHT.

* LOW CONFIDENCE IN MORNING LOW CLOUDS AT ORD WITH MEDIUM
CONFIDENCE AT MDW. HIGH CONFIDENCE THAT ANY CLOUDS WILL SCATTER
BY EARLY TO MID AFTERNOON.

RC/MTF

//OUTLOOK FOR ORD/MDW FOR 00Z MONDAY-12Z SATURDAY...UPDATED 12Z...

SUNDAY NIGHT...VFR. SLOWLY DIMINISHING WINDS.

MONDAY...CHANCE SHRA. MVFR CIGS POSSIBLE.

TUESDAY...VFR LIKELY. BREEZY WEST WINDS.

WEDNESDAY...VFR.

THURSDAY...VFR. SLIGHT CHANCE SHRA LATE.

FRIDAY...CHANCE SHRA AND MVFR CIGS.

MTF

&&

.MARINE...
217 PM CST

DEEPENING LOW PRESSURE MOVING ACROSS THE INTERNATIONAL BORDER OF
MN TONIGHT AND INTO WESTERN ONTARIO ON SUNDAY WILL HAVE A LARGE
INFLUENCE ON LAKE MICHIGAN. SMALL CRAFT ADVISORY CONDITIONS ARE
BEING SPORADICALLY OBSERVED ALREADY...WITH 25 KT GUSTS SEEN ON OR
NEAR THE ILLINOIS SHORE. SOUTHERLY WIND SPEEDS WILL ONLY BE ON THE
INCREASE INTO TONIGHT WITH GALE CONDITIONS EXPECTED TO DEVELOP
PRIOR TO MIDNIGHT INCLUDING IN THE NEAR SHORE AREAS. THE WIND
DIRECTION MAY VARY SOME BETWEEN SOUTH AND SOUTHWEST ALL THE WAY
THROUGH SUNDAY MORNING...BECOMING A MORE DEFINED SOUTHWEST BY
SUNDAY AFTERNOON. HIGHER END GALES TO 45 KTS ARE MOST LIKELY AFTER
MORNING CLOUDS SCOUR AND THE COLD FRONT PASSES...WHICH IS EXPECTED
DURING THE EARLY TO MID AFTERNOON ON SUNDAY. THE MOST FAVORED
PORTION OF THE LAKE TO SEE THESE IS THE SOUTHERN HALF. SOME OF
THESE HIGHER END GUSTS COULD BE SEEN IN THE NEAR SHORE ZONES AS
WELL...PRIMARILY FROM NORTHERLY ISLAND AROUND TO MICHIGAN CITY.
WHILE GALES WILL SLOWLY SUBSIDE LATER SUNDAY NIGHT...THE OVERALL
PROGRESSIVE PATTERN OF LOW PRESSURES WILL CONTINUE THROUGH EARLY
WEDNESDAY. THE NEXT ROUND OF GALES IS FAVORED ON TUESDAY NIGHT AS
LOW PRESSURE MOVES EAST NEAR OR OVER LAKE SUPERIOR DRIVING A WELL-
DEFINED COLD FRONT EAST ACROSS LAKE MICHIGAN. WESTERLY GALES TO 35
KTS AT THIS TIME ARE FAVORED OVER THE NORTHERN HALF OF THE LAKE.

MTF

&&

.LOT WATCHES/WARNINGS/ADVISORIES...
IL...WIND ADVISORY...ILZ005-ILZ006-ILZ010-ILZ011-ILZ012-ILZ013-ILZ014-
ILZ019-ILZ020-ILZ021-ILZ022-ILZ023-ILZ032-ILZ033-ILZ039...8
AM SUNDAY TO 6 PM SUNDAY.

IN...WIND ADVISORY...INZ001-INZ002-INZ010-INZ011-INZ019...8 AM SUNDAY
TO 6 PM SUNDAY.

LM...GALE WARNING...LMZ080-LMZ261-LMZ362-LMZ364-LMZ366-LMZ563-LMZ565-
LMZ567-LMZ669-LMZ671-LMZ673-LMZ675-LMZ740-LMZ741-LMZ742-
LMZ743-LMZ744-LMZ745-LMZ777-LMZ779-LMZ868-LMZ870-LMZ872-
LMZ874-LMZ876-LMZ878...9 PM SATURDAY TO 9 PM SUNDAY.

SMALL CRAFT ADVISORY...NEARSHORE WATERS
UNTIL 9 PM SATURDAY.

&&

$$

Area Forecast Discussion 14:25:01.5138198

.DISCUSSION...
309 AM CST

AN ACTIVE FEW DAYS LAY AHEAD WITH THE MAIN FORECAST CONCERNS
CENTERED AROUND WINDS AND PRECIP CHANCES. EARLY MORNING WATER VAPOR
IMAGERY SHOWS A CORRIDOR OF FAIRLY FLAT UPPER FLOW OVER THE EASTERN
HALF OF THE COUNTRY WITH SLIGHT UPPER RIDGING TRANSLATING EASTWARD
ACROSS THE NORTHERN PLAINS AND UPPER MISSISSIPPI RIVER VALLEY. TO
THE WEST...A SERIES OF SHORTWAVES ARE LINED UP WITH ONE DIGGING INTO
WESTERN MONTANA AND ANOTHER MOVING ALONG THE SOUTHEASTERN ALASKAN
COAST TOWARD FAR NORTHERN BRITISH COLUMBIA. ANOTHER UPPER TROUGH IS
CUT OFF FROM THIS NORTHERN STREAM OF FLOW JUST OFF THE CALIFORNIA
COAST AND WILL PLAY A ROLE IN PRECIP CHANCES FOR OUR AREA EARLY NEXT
WEEK. AT THE SURFACE...LOW PRESSURE WAS OBSERVED JUST NORTHEAST OF
LAKE SUPERIOR. ANOTHER SURFACE LOW IS DEVELOPING OVER SOUTHERN
SASKATCHEWAN/CENTRAL MONTANA AS A RESULT OF THE AFOREMENTIONED UPPER
SHORTWAVE WITH A SUBTLE WARM FRONT/TROUGH ANALYZED FROM THE LOW
ARCHING SOUTHEASTWARD ACROSS NORTHERN ILLINOIS AND INDIANA. THIS LOW
WILL BE KEY IN BRINGING INCREASING WINDS TO THE REGION TONIGHT AND
SUNDAY.

TODAY...AM EXPECTING A MILDER DAY TODAY WITH WARM ADVECTION ONGOING
EARLY THIS MORNING. SOUTH WINDS WILL INCREASE EARLY THIS AFTERNOON
AND BECOME SOMEWHAT GUSTY AS THE PRESSURE GRADIENT TIGHTENS WITH THE
SURFACE LOW DEEPENING OVER THE NORTHERN PLAINS. MIXING TO BETWEEN
950 AND 925 MB IS EXPECTED TODAY RESULTING IN GUSTS AROUND 20 KT AT
TIMES AND HIGHS IN THE MID 50S NORTH TO UPPER 50S SOUTH OF
INTERSTATE 88...WITH A FEW AREAS POSSIBLY REACHING 60 DEGREES MAINLY
SOUTH OF INTERSTATE 80 THANKS TO THE BREEZY SOUTH-SOUTHWEST WINDS.

TONIGHT THROUGH SUNDAY NIGHT...THE SURFACE LOW WILL MOVE FROM
EASTERN NORTH DAKOTA INTO WESTERN ONTARIO TONIGHT WHILE DEEPENING
INTO THE 980-985 MB RANGE. WINDS AND TEMPS WILL BE TRICKY AS THEY
WILL BE DICTATED BY THE DECOUPLING OF THE BOUNDARY LAYER THIS
EVENING. AM THINKING THAT DECOUPLING MAY OCCUR WITH SUNSET LATE THIS
AFTERNOON ALLOWING GUSTS TO DIMINISH BUT THE TIGHTENING PRESSURE
GRADIENT WILL KEEP SUSTAINED WIND SPEEDS UP. THIS WOULD LEAD TO
LITTLE DROP OFF IN TEMPS THIS EVENING. A WEAK UPPER WAVE LOOKS TO
LIFT NORTHEASTWARD ACROSS THE AREA THIS EVENING BRINGING MODEST MID
LEVEL COOL ADVECTION FOR A SHORT TIME AND MAY SERVE AS A CATALYST
FOR MIXING TO RE-DEVELOP LEADING TO A RETURN OF WIND GUSTS. THE
CONCERN IS THAT THE LOW LEVEL JET RAMPS UP SIGNIFICANTLY THIS
EVENING WITH FORECAST SOUNDINGS INDICATING 30+ KT WINDS STARTING
AROUND 600 FT AGL AND 40+ KT WINDS AT 1000 FT WITH A PEAK AT AROUND
60 KT UP AROUND 2500 FT. ITS NOT OUT OF THE QUESTION THAT 30 KT
GUSTS COULD OCCUR OVERNIGHT. ANOTHER WARM FRONT LOOKS TO QUICKLY
CROSS THE AREA EARLY SUNDAY MORNING WITH A LOW LEVEL THERMAL AXIS
CRESTING THE AREA. WINDS BECOME A BIGGER ISSUE SUNDAY AS MIXING
COMMENCES. THE LOW WILL BE LIFTING NORTHEASTWARD TOWARDS SOUTHERN
HUDSON BAY AND LIKELY BE SOMEWHERE AROUND 980 MB. PEAK LOW LEVEL
WINDS DO SUBSIDE BUT A DEEP LAYER OF 40-50 KT WINDS CONTINUES INTO
EARLY SUNDAY AFTERNOON. MIXING SUPPORTS GUSTS TO NEAR 40 KT DURING
THE DAY WITH POTENTIAL FOR A BRIEF PERIOD OF HIGHER GUSTS OF 45 KT
OR POSSIBLY HIGHER AS THE COLD FRONT PASSES AROUND MIDDAY. PRECIP
CHANCES ARE NOT IMPRESSIVE WITH DEEP LAYER MOISTURE LACKING SO WILL
CONTINUE WITH SLIGHT AND LOW CHANCE POPS BUT THESE MAY EVEN BE TOO
HIGH. WINDS WILL DIMINISH OVER LAND AREAS SUNDAY EVENING.

MONDAY THROUGH WEDNESDAY...THE COOL FRONTAL BOUNDARY WILL WEAKEN AND
WASH OUT TO THE SOUTH AND EAST OF THE AREA SUNDAY NIGHT INTO MONDAY
BUT STILL BE INTACT ENOUGH TO KEEP A BELT OF POOLED MOISTURE FROM
THE LOWER LAKES INTO CENTRAL ILLINOIS. THE ALASKAN UPPER WAVE WILL
DAMPEN BUT THE NORTHERN STREAM WILL BEGIN TO PHASE WITH THE
CALIFORNIA CUTOFF UPPER LOW. A LEAD SHORTWAVE WILL EJECT
NORTHEASTWARD FROM THE CENTRAL PLAINS AHEAD OF THE DEVELOPING
LONGWAVE TROUGH AXIS AND PUSH A WEAK SURFACE TROUGH ALONG THE OLD
FRONT/AREA OF POOLED MOISTURE MONDAY. THIS SHOULD PUSH THE MOISTURE
NORTHWARD AND BACK INTO MOST OF THE FORECAST AREA MONDAY MORNING.
THIS WILL SUPPORT INCREASED RAIN CHANCES...PRIMARILY ACROSS THE
SOUTHEAST TWO-THIRDS TO THREE-QUARTERS OF THE AREA MONDAY. THE
LARGER SCALE UPPER TROUGH WILL SWING ACROSS THE AREA AS IT AMPLIFIES
TUESDAY WITH ANOTHER SURFACE LOW MOVING FROM THE UPPER MISSISSIPPI
RIVER VALLEY INTO WESTERN ONTARIO. ANOTHER SHARP COLD FRONT WILL
CROSS THE AREA LATER TUESDAY AFTERNOON OR EARLY TUESDAY EVENING.
ANOTHER PERIOD OF GUSTY WINDS IS EXPECTED WITH THE STRONG COLD
ADVECTION AS H85 TEMPS FALL BACK TO THE -6 OR -8 C RANGE INTO
WEDNESDAY FROM THEIR ABOVE ZERO C READINGS PRIOR TO THAT.

THURSDAY AND FRIDAY...DRIER WEATHER WILL RETURN INTO THURSDAY AS
HIGH PRESSURE MOVES SOUTH OF THE AREA BUT THE UPPER FLOW PATTERN
WILL REMAIN ACTIVE JUST TO THE NORTH OF THE AREA. THEREFORE CANNOT
RULE OUT A WAVE MOVING CLOSE ENOUGH TO THE AREA TO KICK OFF SOME
SHOWERS ESPECIALLY AS WARM ADVECTION RETURNS THURSDAY NIGHT. THE
UPPER FLOW WILL TURN SOUTHWESTERLY SUGGESTING A RETURN TO MORE
ACTIVE WEATHER NEXT WEEKEND THOUGH WE SHOULD SEE AN UPSWING IN TEMPS
BY THAT TIME.

MDB

&&

.AVIATION...

//ORD AND MDW CONCERNS...UPDATED 18Z...

* SOUTH WIND GUSTS OF 20 TO 25 KTS THROUGH TONIGHT AND SOUTHWEST
WINDS UP TO 40 KTS BY SUNDAY AFTERNOON.

* LOW-LEVEL WIND SHEAR TONIGHT.

* LOW CLOUD LIKELIHOOD LATE TONIGHT INTO SUNDAY MORNING.

//DISCUSSION...UPDATED 18Z...

LOW PRESSURE WILL CONTINUE TO DEEPEN AS IT EVOLVES EAST ALONG THE
INTERNATIONAL BORDER OF ND/MN INTO TONIGHT. THIS WILL LEAD TO A
TIGHTENING PRESSURE GRADIENT ACROSS THE TAF SITES TONIGHT AND KEEP
SUSTAINED WINDS UP...POTENTIALLY EVEN INCREASING SLIGHTLY.
OCCASIONAL GUSTS TO 20 TO 25 KTS ARE LIKELY. ALSO BECAUSE OF THE
LOW DEEPENING...A SOUTHWEST LOW-LEVEL JET WILL FOCUS ATOP THE
AREA WITHIN THE 1500 TO 3000 FT LAYER. SPEEDS AS HIGH AS 55-60 KTS
ARE POSSIBLE IN THIS LAYER OVERNIGHT...POTENTIALLY CREATING PLANE
SPACING ISSUES THROUGH LOW-LEVEL WIND SHEAR. THESE STRONG
SOUTHERLY WINDS JUST OFF THE SURFACE TONIGHT WILL STEER MOISTURE
BACK AND WITH THAT WILL COME THE LIKELIHOOD OF MVFR AND POSSIBLY
IFR CEILINGS. AT LEAST SOME SCATTERED MORNING CLOUDS ARE
EXPECTED...WITH BROKEN CEILINGS BECOMING MORE FAVORED THAN THE
LAST FORECAST. SCATTERED LIGHT SHOWERS AND AREAS OF DRIZZLE ARE
POSSIBLE...MOST FAVORED SOUTH OF THE TAF SITES. AS THE
AFOREMENTIONED LOW PRESSURE WRAPS DRY AIR IN FROM THE WEST...THE
CLOUDS SHOULD PUSH EAST BY AFTERNOON. WITH THAT DRY SURGE HOWEVER
WILL COME EVEN GUSTIER AND HIGHER IMPACT SOUTHWEST SURFACE
WINDS...POTENTIALLY UP TO 45 KTS.

//ORD AND MDW CONFIDENCE...UPDATED 18Z...

* HIGH CONFIDENCE IN PERIODIC SOUTH WIND GUSTS TO 20 KTS THROUGH
DAYBREAK SUNDAY.

* HIGH CONFIDENCE IN SOUTHWEST GUSTS REACHING AT LEAST 35 KTS ON
SUNDAY AFTERNOON...WITH POTENTIAL FOR SOME OF THESE GUSTS
ALREADY IN THE MORNING.

* HIGH CONFIDENCE IN AT LEAST 45 KT SOUTHWEST FLOW WITHIN THE 1500
TO 3000 FT LAYER TONIGHT.

* LOW CONFIDENCE IN MORNING LOW CLOUDS AT ORD WITH MEDIUM
CONFIDENCE AT MDW. HIGH CONFIDENCE THAT ANY CLOUDS WILL SCATTER
BY EARLY TO MID AFTERNOON.

//OUTLOOK FOR ORD/MDW FOR 00Z MONDAY-12Z SATURDAY...UPDATED 12Z...

SUNDAY NIGHT...VFR. SLOWLY DIMINISHING WINDS.

MONDAY...CHANCE SHRA. MVFR CIGS POSSIBLE.

TUESDAY...VFR LIKELY. BREEZY WEST WINDS.

WEDNESDAY...VFR.

THURSDAY...VFR. SLIGHT CHANCE SHRA LATE.

FRIDAY...CHANCE SHRA AND MVFR CIGS.

MTF

&&

.MARINE...
217 PM CST

DEEPENING LOW PRESSURE MOVING ACROSS THE INTERNATIONAL BORDER OF
MN TONIGHT AND INTO WESTERN ONTARIO ON SUNDAY WILL HAVE A LARGE
INFLUENCE ON LAKE MICHIGAN. SMALL CRAFT ADVISORY CONDITIONS ARE
BEING SPORADICALLY OBSERVED ALREADY...WITH 25 KT GUSTS SEEN ON OR
NEAR THE ILLINOIS SHORE. SOUTHERLY WIND SPEEDS WILL ONLY BE ON THE
INCREASE INTO TONIGHT WITH GALE CONDITIONS EXPECTED TO DEVELOP
PRIOR TO MIDNIGHT INCLUDING IN THE NEAR SHORE AREAS. THE WIND
DIRECTION MAY VARY SOME BETWEEN SOUTH AND SOUTHWEST ALL THE WAY
THROUGH SUNDAY MORNING...BECOMING A MORE DEFINED SOUTHWEST BY
SUNDAY AFTERNOON. HIGHER END GALES TO 45 KTS ARE MOST LIKELY AFTER
MORNING CLOUDS SCOUR AND THE COLD FRONT PASSES...WHICH IS EXPECTED
DURING THE EARLY TO MID AFTERNOON ON SUNDAY. THE MOST FAVORED
PORTION OF THE LAKE TO SEE THESE IS THE SOUTHERN HALF. SOME OF
THESE HIGHER END GUSTS COULD BE SEEN IN THE NEAR SHORE ZONES AS
WELL...PRIMARILY FROM NORTHERLY ISLAND AROUND TO MICHIGAN CITY.
WHILE GALES WILL SLOWLY SUBSIDE LATER SUNDAY NIGHT...THE OVERALL
PROGRESSIVE PATTERN OF LOW PRESSURES WILL CONTINUE THROUGH EARLY
WEDNESDAY. THE NEXT ROUND OF GALES IS FAVORED ON TUESDAY NIGHT AS
LOW PRESSURE MOVES EAST NEAR OR OVER LAKE SUPERIOR DRIVING A WELL-
DEFINED COLD FRONT EAST ACROSS LAKE MICHIGAN. WESTERLY GALES TO 35
KTS AT THIS TIME ARE FAVORED OVER THE NORTHERN HALF OF THE LAKE.

MTF

&&

.LOT WATCHES/WARNINGS/ADVISORIES...
IL...WIND ADVISORY...ILZ005-ILZ006-ILZ010-ILZ011-ILZ012-ILZ013-ILZ014-
ILZ019-ILZ020-ILZ021-ILZ022-ILZ023-ILZ032-ILZ033-ILZ039...8
AM SUNDAY TO 6 PM SUNDAY.

IN...WIND ADVISORY...INZ001-INZ002-INZ010-INZ011-INZ019...8 AM SUNDAY
TO 6 PM SUNDAY.

LM...GALE WARNING...LMZ080-LMZ261-LMZ362-LMZ364-LMZ366-LMZ563-LMZ565-
LMZ567-LMZ669-LMZ671-LMZ673-LMZ675-LMZ740-LMZ741-LMZ742-
LMZ743-LMZ744-LMZ745-LMZ777-LMZ779-LMZ868-LMZ870-LMZ872-
LMZ874-LMZ876-LMZ878...9 PM SATURDAY TO 9 PM SUNDAY.

SMALL CRAFT ADVISORY...NEARSHORE WATERS
UNTIL 9 PM SATURDAY.

&&

$$

Area Forecast Discussion 12:09:10.4331250

.DISCUSSION...
309 AM CST

AN ACTIVE FEW DAYS LAY AHEAD WITH THE MAIN FORECAST CONCERNS
CENTERED AROUND WINDS AND PRECIP CHANCES. EARLY MORNING WATER VAPOR
IMAGERY SHOWS A CORRIDOR OF FAIRLY FLAT UPPER FLOW OVER THE EASTERN
HALF OF THE COUNTRY WITH SLIGHT UPPER RIDGING TRANSLATING EASTWARD
ACROSS THE NORTHERN PLAINS AND UPPER MISSISSIPPI RIVER VALLEY. TO
THE WEST...A SERIES OF SHORTWAVES ARE LINED UP WITH ONE DIGGING INTO
WESTERN MONTANA AND ANOTHER MOVING ALONG THE SOUTHEASTERN ALASKAN
COAST TOWARD FAR NORTHERN BRITISH COLUMBIA. ANOTHER UPPER TROUGH IS
CUT OFF FROM THIS NORTHERN STREAM OF FLOW JUST OFF THE CALIFORNIA
COAST AND WILL PLAY A ROLE IN PRECIP CHANCES FOR OUR AREA EARLY NEXT
WEEK. AT THE SURFACE...LOW PRESSURE WAS OBSERVED JUST NORTHEAST OF
LAKE SUPERIOR. ANOTHER SURFACE LOW IS DEVELOPING OVER SOUTHERN
SASKATCHEWAN/CENTRAL MONTANA AS A RESULT OF THE AFOREMENTIONED UPPER
SHORTWAVE WITH A SUBTLE WARM FRONT/TROUGH ANALYZED FROM THE LOW
ARCHING SOUTHEASTWARD ACROSS NORTHERN ILLINOIS AND INDIANA. THIS LOW
WILL BE KEY IN BRINGING INCREASING WINDS TO THE REGION TONIGHT AND
SUNDAY.

TODAY...AM EXPECTING A MILDER DAY TODAY WITH WARM ADVECTION ONGOING
EARLY THIS MORNING. SOUTH WINDS WILL INCREASE EARLY THIS AFTERNOON
AND BECOME SOMEWHAT GUSTY AS THE PRESSURE GRADIENT TIGHTENS WITH THE
SURFACE LOW DEEPENING OVER THE NORTHERN PLAINS. MIXING TO BETWEEN
950 AND 925 MB IS EXPECTED TODAY RESULTING IN GUSTS AROUND 20 KT AT
TIMES AND HIGHS IN THE MID 50S NORTH TO UPPER 50S SOUTH OF
INTERSTATE 88...WITH A FEW AREAS POSSIBLY REACHING 60 DEGREES MAINLY
SOUTH OF INTERSTATE 80 THANKS TO THE BREEZY SOUTH-SOUTHWEST WINDS.

TONIGHT THROUGH SUNDAY NIGHT...THE SURFACE LOW WILL MOVE FROM
EASTERN NORTH DAKOTA INTO WESTERN ONTARIO TONIGHT WHILE DEEPENING
INTO THE 980-985 MB RANGE. WINDS AND TEMPS WILL BE TRICKY AS THEY
WILL BE DICTATED BY THE DECOUPLING OF THE BOUNDARY LAYER THIS
EVENING. AM THINKING THAT DECOUPLING MAY OCCUR WITH SUNSET LATE THIS
AFTERNOON ALLOWING GUSTS TO DIMINISH BUT THE TIGHTENING PRESSURE
GRADIENT WILL KEEP SUSTAINED WIND SPEEDS UP. THIS WOULD LEAD TO
LITTLE DROP OFF IN TEMPS THIS EVENING. A WEAK UPPER WAVE LOOKS TO
LIFT NORTHEASTWARD ACROSS THE AREA THIS EVENING BRINGING MODEST MID
LEVEL COOL ADVECTION FOR A SHORT TIME AND MAY SERVE AS A CATALYST
FOR MIXING TO RE-DEVELOP LEADING TO A RETURN OF WIND GUSTS. THE
CONCERN IS THAT THE LOW LEVEL JET RAMPS UP SIGNIFICANTLY THIS
EVENING WITH FORECAST SOUNDINGS INDICATING 30+ KT WINDS STARTING
AROUND 600 FT AGL AND 40+ KT WINDS AT 1000 FT WITH A PEAK AT AROUND
60 KT UP AROUND 2500 FT. ITS NOT OUT OF THE QUESTION THAT 30 KT
GUSTS COULD OCCUR OVERNIGHT. ANOTHER WARM FRONT LOOKS TO QUICKLY
CROSS THE AREA EARLY SUNDAY MORNING WITH A LOW LEVEL THERMAL AXIS
CRESTING THE AREA. WINDS BECOME A BIGGER ISSUE SUNDAY AS MIXING
COMMENCES. THE LOW WILL BE LIFTING NORTHEASTWARD TOWARDS SOUTHERN
HUDSON BAY AND LIKELY BE SOMEWHERE AROUND 980 MB. PEAK LOW LEVEL
WINDS DO SUBSIDE BUT A DEEP LAYER OF 40-50 KT WINDS CONTINUES INTO
EARLY SUNDAY AFTERNOON. MIXING SUPPORTS GUSTS TO NEAR 40 KT DURING
THE DAY WITH POTENTIAL FOR A BRIEF PERIOD OF HIGHER GUSTS OF 45 KT
OR POSSIBLY HIGHER AS THE COLD FRONT PASSES AROUND MIDDAY. PRECIP
CHANCES ARE NOT IMPRESSIVE WITH DEEP LAYER MOISTURE LACKING SO WILL
CONTINUE WITH SLIGHT AND LOW CHANCE POPS BUT THESE MAY EVEN BE TOO
HIGH. WINDS WILL DIMINISH OVER LAND AREAS SUNDAY EVENING.

MONDAY THROUGH WEDNESDAY...THE COOL FRONTAL BOUNDARY WILL WEAKEN AND
WASH OUT TO THE SOUTH AND EAST OF THE AREA SUNDAY NIGHT INTO MONDAY
BUT STILL BE INTACT ENOUGH TO KEEP A BELT OF POOLED MOISTURE FROM
THE LOWER LAKES INTO CENTRAL ILLINOIS. THE ALASKAN UPPER WAVE WILL
DAMPEN BUT THE NORTHERN STREAM WILL BEGIN TO PHASE WITH THE
CALIFORNIA CUTOFF UPPER LOW. A LEAD SHORTWAVE WILL EJECT
NORTHEASTWARD FROM THE CENTRAL PLAINS AHEAD OF THE DEVELOPING
LONGWAVE TROUGH AXIS AND PUSH A WEAK SURFACE TROUGH ALONG THE OLD
FRONT/AREA OF POOLED MOISTURE MONDAY. THIS SHOULD PUSH THE MOISTURE
NORTHWARD AND BACK INTO MOST OF THE FORECAST AREA MONDAY MORNING.
THIS WILL SUPPORT INCREASED RAIN CHANCES...PRIMARILY ACROSS THE
SOUTHEAST TWO-THIRDS TO THREE-QUARTERS OF THE AREA MONDAY. THE
LARGER SCALE UPPER TROUGH WILL SWING ACROSS THE AREA AS IT AMPLIFIES
TUESDAY WITH ANOTHER SURFACE LOW MOVING FROM THE UPPER MISSISSIPPI
RIVER VALLEY INTO WESTERN ONTARIO. ANOTHER SHARP COLD FRONT WILL
CROSS THE AREA LATER TUESDAY AFTERNOON OR EARLY TUESDAY EVENING.
ANOTHER PERIOD OF GUSTY WINDS IS EXPECTED WITH THE STRONG COLD
ADVECTION AS H85 TEMPS FALL BACK TO THE -6 OR -8 C RANGE INTO
WEDNESDAY FROM THEIR ABOVE ZERO C READINGS PRIOR TO THAT.

THURSDAY AND FRIDAY...DRIER WEATHER WILL RETURN INTO THURSDAY AS
HIGH PRESSURE MOVES SOUTH OF THE AREA BUT THE UPPER FLOW PATTERN
WILL REMAIN ACTIVE JUST TO THE NORTH OF THE AREA. THEREFORE CANNOT
RULE OUT A WAVE MOVING CLOSE ENOUGH TO THE AREA TO KICK OFF SOME
SHOWERS ESPECIALLY AS WARM ADVECTION RETURNS THURSDAY NIGHT. THE
UPPER FLOW WILL TURN SOUTHWESTERLY SUGGESTING A RETURN TO MORE
ACTIVE WEATHER NEXT WEEKEND THOUGH WE SHOULD SEE AN UPSWING IN TEMPS
BY THAT TIME.

MDB

&&

.AVIATION...

//ORD AND MDW CONCERNS...UPDATED 18Z...

* SOUTH WIND GUSTS OF 20 TO 25 KTS THROUGH TONIGHT AND SOUTHWEST
UP TO 40 KTS BY SUNDAY AFTERNOON.

* LOW-LEVEL WIND SHEAR TONIGHT.

* LOW CLOUD LIKELIHOOD LATE TONIGHT INTO SUNDAY MORNING.

//DISCUSSION...UPDATED 18Z...

LOW PRESSURE WILL CONTINUE TO DEEPEN AS IT EVOLVES EAST ALONG THE
INTERNATIONAL BORDER OF ND/MN INTO TONIGHT. THIS WILL LEAD TO A
TIGHTENING PRESSURE GRADIENT ACROSS THE TAF SITES TONIGHT AND KEEP
SUSTAINED WINDS UP...POTENTIALLY EVEN INCREASING SLIGHTLY.
OCCASIONAL GUSTS TO 20 TO 25 KTS ARE LIKELY. ALSO BECAUSE OF THE
LOW DEEPENING...A SOUTHWEST LOW-LEVEL JET WILL FOCUS ATOP THE
AREA WITHIN THE 1500 TO 3000 FT LAYER. SPEEDS AS HIGH AS 55-60 KTS
ARE POSSIBLE IN THIS LAYER OVERNIGHT...POTENTIALLY CREATING PLANE
SPACING ISSUES THROUGH LOW-LEVEL WIND SHEAR. THESE STRONG
SOUTHERLY WINDS JUST OFF THE SURFACE TONIGHT WILL STEER MOISTURE
BACK AND WITH THAT WILL COME THE LIKELIHOOD OF MVFR AND POSSIBLY
IFR CEILINGS. AT LEAST SOME SCATTERED MORNING CLOUDS ARE
EXPECTED...WITH BROKEN CEILINGS BECOMING MORE FAVORED THAN THE
LAST FORECAST. SCATTERED LIGHT SHOWERS AND AREAS OF DRIZZLE ARE
POSSIBLE...MOST FAVORED SOUTH OF THE TAF SITES. AS THE
AFOREMENTIONED LOW PRESSURE WRAPS DRY AIR IN FROM THE WEST...THE
CLOUDS SHOULD PUSH EAST BY AFTERNOON. WITH THAT DRY SURGE HOWEVER
WILL COME EVEN GUSTIER AND HIGHER IMPACT SOUTHWEST SURFACE
WINDS...POTENTIALLY UP TO 45 KTS.

//ORD AND MDW CONFIDENCE...UPDATED 18Z...

* HIGH CONFIDENCE IN PERIODIC SOUTH WIND GUSTS TO 20 KTS THROUGH
DAYBREAK SUNDAY.

* HIGH CONFIDENCE IN SOUTHWEST GUSTS REACHING AT LEAST 35 KTS ON
SUNDAY AFTERNOON...WITH POTENTIAL FOR SOME OF THESE GUSTS
ALREADY IN THE MORNING.

* HIGH CONFIDENCE IN AT LEAST 45 KT SOUTHWEST FLOW WITHIN THE 1500
TO 3000 FT LAYER TONIGHT.

* LOW CONFIDENCE IN MORNING LOW CLOUDS AT ORD WITH MEDIUM
CONFIDENCE AT MDW. HIGH CONFIDENCE THAT ANY CLOUDS WILL SCATTER
BY EARLY TO MID AFTERNOON.

//OUTLOOK FOR ORD/MDW FOR 00Z MONDAY-12Z SATURDAY...UPDATED 12Z...

SUNDAY NIGHT...VFR. SLOWLY DIMINISHING WINDS.

MONDAY...CHANCE SHRA. MVFR CIGS POSSIBLE.

TUESDAY...VFR LIKELY. BREEZY WEST WINDS.

WEDNESDAY...VFR.

THURSDAY...VFR. SLIGHT CHANCE SHRA LATE.

FRIDAY...CHANCE SHRA AND MVFR CIGS.

MTF

&&

.MARINE...

UPDATE...914 AM CST

OBSERVATIONS ACROSS THE NEAR SHORE ZONES AND NEARBY LAND
OBSERVATIONS INDICATE SOUTHWEST WIND SPEEDS ARE ON THE CLIMB
QUICKLY THIS MORNING. WITH 25 KT WINDS AT 2K FT AS SEEN ON LOCAL
RADAR LIKELY ABLE TO BE MIXED DOWN IN GUSTS...IT APPEARS SMALL
CRAFT ADVISORY CONDITIONS WILL BEGIN ENOUGH IN ADVANCE OF THE GALE
WARNING TO WARRANT THAT HEADLINE ISSUANCE. WILL BEGIN THE SMALL
CRAFT ADVISORY AT 3 PM.

MTF

300 AM CST

THROUGH THE NIGHT...WINDS HAVE BEEN DROPPING OFF AS LOW PRESSURE
OVER THE UPPER GREAT LAKES LIFTS TO THE NORTHEAST AND WEAKENS.
HOWEVER...WINDS WILL STRENGTHEN AGAIN LATER THIS AFTERNOON AND
EVENING AS LOW PRESSURE DROPS INTO THE NORTHERN PLAINS LATER
TODAY. SOUTH WINDS WILL QUICKLY INCREASE EARLY THIS EVENING TO
SOUTH GALES AS THE LOW RAPIDLY DEEPENS WHILE LIFTING NORTHEAST TO
HUDSON BAY. WINDS WILL BRIEFLY SUBSIDE BELOW GALE FORCE MONDAY
AND TUESDAY...BUT ANOTHER DEEP LOW IS EXPECTED TO DRAG A STRONG
COLD FRONT ACROSS THE LAKE TUESDAY EVENING. THE STRONG COLD
ADVECTION BEHIND THIS FRONT WILL USHER IN ANOTHER ROUND OF GALES
FOR TUESDAY NIGHT AND WEDNESDAY.

KREIN

&&

.LOT WATCHES/WARNINGS/ADVISORIES...
IL...NONE.
IN...NONE.
LM...SMALL CRAFT ADVISORY...LMZ740-LMZ741-LMZ742-LMZ743-LMZ744-
LMZ745...3 PM SATURDAY TO 9 PM SATURDAY.

GALE WARNING...LMZ080-LMZ261-LMZ362-LMZ364-LMZ366-LMZ563-LMZ565-
LMZ567-LMZ669-LMZ671-LMZ673-LMZ675-LMZ740-LMZ741-LMZ742-
LMZ743-LMZ744-LMZ745-LMZ777-LMZ779-LMZ868-LMZ870-LMZ872-
LMZ874-LMZ876-LMZ878...9 PM SATURDAY TO 9 PM SUNDAY.

&&

$$

Zone Forecast 10:54:37.3888423

.REST OF TODAY...PARTLY CLOUDY. HIGHS IN THE MID 50S. SOUTH WINDS
10 TO 15 MPH.
.TONIGHT...MOSTLY CLOUDY. BREEZY. LOWS IN THE UPPER 40S. SOUTH
WINDS 15 TO 25 MPH WITH GUSTS UP TO 30 MPH AT TIMES.
.SUNDAY...WINDY. MOSTLY CLOUDY WITH A 20 PERCENT CHANCE OF LIGHT
SHOWERS. HIGHS IN THE MID 50S. SOUTHWEST WINDS 20 TO 30 MPH.
GUSTS UP TO 30 MPH EARLY IN THE MORNING INCREASING TO 45 MPH IN
THE LATE MORNING AND AFTERNOON.
.SUNDAY NIGHT...PARTLY CLOUDY. LOWS IN THE UPPER 30S. SOUTHWEST
WINDS 10 TO 15 MPH. GUSTS UP TO 30 MPH IN THE EVENING.
.MONDAY...PARTLY SUNNY WITH A 30 PERCENT CHANCE OF SHOWERS. HIGHS
IN THE LOWER 50S. SOUTH WINDS 10 TO 15 MPH.
.MONDAY NIGHT...PARTLY CLOUDY. LOWS IN THE UPPER 30S.
.TUESDAY...PARTLY CLOUDY. HIGHS IN THE LOWER 50S.
.TUESDAY NIGHT...MOSTLY CLEAR. LOWS AROUND 30.
.WEDNESDAY THROUGH THURSDAY NIGHT...PARTLY CLOUDY. HIGHS IN THE
LOWER 40S. LOWS AROUND 30.
.FRIDAY...PARTLY SUNNY WITH A 20 PERCENT CHANCE OF RAIN. HIGHS
AROUND 50.

Hazardous Weather Outlook 09:47:17.3488463

THIS HAZARDOUS WEATHER OUTLOOK IS FOR NORTH CENTRAL ILLINOIS...
NORTHEAST ILLINOIS AND NORTHWEST INDIANA.

.DAY ONE...TODAY AND TONIGHT.

NO HAZARDOUS WEATHER IS EXPECTED AT THIS TIME.

.DAYS TWO THROUGH SEVEN...SUNDAY THROUGH FRIDAY.

SOUTHWEST WINDS OF 25 TO 35 MPH WITH GUSTS AROUND 50 MPH ARE
POSSIBLE ON SUNDAY.

.SPOTTER INFORMATION STATEMENT...

SPOTTER ACTIVATION WILL NOT BE NECESSARY THROUGH TONIGHT.

&&

COMPLETE FORECAST INFORMATION IS AVAILABLE ON THE NWS CHICAGO
WEBPAGE: WEATHER.GOV/CHICAGO

Area Forecast Discussion 09:19:26.3323033

.DISCUSSION...
309 AM CST

AN ACTIVE FEW DAYS LAY AHEAD WITH THE MAIN FORECAST CONCERNS
CENTERED AROUND WINDS AND PRECIP CHANCES. EARLY MORNING WATER VAPOR
IMAGERY SHOWS A CORRIDOR OF FAIRLY FLAT UPPER FLOW OVER THE EASTERN
HALF OF THE COUNTRY WITH SLIGHT UPPER RIDGING TRANSLATING EASTWARD
ACROSS THE NORTHERN PLAINS AND UPPER MISSISSIPPI RIVER VALLEY. TO
THE WEST...A SERIES OF SHORTWAVES ARE LINED UP WITH ONE DIGGING INTO
WESTERN MONTANA AND ANOTHER MOVING ALONG THE SOUTHEASTERN ALASKAN
COAST TOWARD FAR NORTHERN BRITISH COLUMBIA. ANOTHER UPPER TROUGH IS
CUT OFF FROM THIS NORTHERN STREAM OF FLOW JUST OFF THE CALIFORNIA
COAST AND WILL PLAY A ROLE IN PRECIP CHANCES FOR OUR AREA EARLY NEXT
WEEK. AT THE SURFACE...LOW PRESSURE WAS OBSERVED JUST NORTHEAST OF
LAKE SUPERIOR. ANOTHER SURFACE LOW IS DEVELOPING OVER SOUTHERN
SASKATCHEWAN/CENTRAL MONTANA AS A RESULT OF THE AFOREMENTIONED UPPER
SHORTWAVE WITH A SUBTLE WARM FRONT/TROUGH ANALYZED FROM THE LOW
ARCHING SOUTHEASTWARD ACROSS NORTHERN ILLINOIS AND INDIANA. THIS LOW
WILL BE KEY IN BRINGING INCREASING WINDS TO THE REGION TONIGHT AND
SUNDAY.

TODAY...AM EXPECTING A MILDER DAY TODAY WITH WARM ADVECTION ONGOING
EARLY THIS MORNING. SOUTH WINDS WILL INCREASE EARLY THIS AFTERNOON
AND BECOME SOMEWHAT GUSTY AS THE PRESSURE GRADIENT TIGHTENS WITH THE
SURFACE LOW DEEPENING OVER THE NORTHERN PLAINS. MIXING TO BETWEEN
950 AND 925 MB IS EXPECTED TODAY RESULTING IN GUSTS AROUND 20 KT AT
TIMES AND HIGHS IN THE MID 50S NORTH TO UPPER 50S SOUTH OF
INTERSTATE 88...WITH A FEW AREAS POSSIBLY REACHING 60 DEGREES MAINLY
SOUTH OF INTERSTATE 80 THANKS TO THE BREEZY SOUTH-SOUTHWEST WINDS.

TONIGHT THROUGH SUNDAY NIGHT...THE SURFACE LOW WILL MOVE FROM
EASTERN NORTH DAKOTA INTO WESTERN ONTARIO TONIGHT WHILE DEEPENING
INTO THE 980-985 MB RANGE. WINDS AND TEMPS WILL BE TRICKY AS THEY
WILL BE DICTATED BY THE DECOUPLING OF THE BOUNDARY LAYER THIS
EVENING. AM THINKING THAT DECOUPLING MAY OCCUR WITH SUNSET LATE THIS
AFTERNOON ALLOWING GUSTS TO DIMINISH BUT THE TIGHTENING PRESSURE
GRADIENT WILL KEEP SUSTAINED WIND SPEEDS UP. THIS WOULD LEAD TO
LITTLE DROP OFF IN TEMPS THIS EVENING. A WEAK UPPER WAVE LOOKS TO
LIFT NORTHEASTWARD ACROSS THE AREA THIS EVENING BRINGING MODEST MID
LEVEL COOL ADVECTION FOR A SHORT TIME AND MAY SERVE AS A CATALYST
FOR MIXING TO RE-DEVELOP LEADING TO A RETURN OF WIND GUSTS. THE
CONCERN IS THAT THE LOW LEVEL JET RAMPS UP SIGNIFICANTLY THIS
EVENING WITH FORECAST SOUNDINGS INDICATING 30+ KT WINDS STARTING
AROUND 600 FT AGL AND 40+ KT WINDS AT 1000 FT WITH A PEAK AT AROUND
60 KT UP AROUND 2500 FT. ITS NOT OUT OF THE QUESTION THAT 30 KT
GUSTS COULD OCCUR OVERNIGHT. ANOTHER WARM FRONT LOOKS TO QUICKLY
CROSS THE AREA EARLY SUNDAY MORNING WITH A LOW LEVEL THERMAL AXIS
CRESTING THE AREA. WINDS BECOME A BIGGER ISSUE SUNDAY AS MIXING
COMMENCES. THE LOW WILL BE LIFTING NORTHEASTWARD TOWARDS SOUTHERN
HUDSON BAY AND LIKELY BE SOMEWHERE AROUND 980 MB. PEAK LOW LEVEL
WINDS DO SUBSIDE BUT A DEEP LAYER OF 40-50 KT WINDS CONTINUES INTO
EARLY SUNDAY AFTERNOON. MIXING SUPPORTS GUSTS TO NEAR 40 KT DURING
THE DAY WITH POTENTIAL FOR A BRIEF PERIOD OF HIGHER GUSTS OF 45 KT
OR POSSIBLY HIGHER AS THE COLD FRONT PASSES AROUND MIDDAY. PRECIP
CHANCES ARE NOT IMPRESSIVE WITH DEEP LAYER MOISTURE LACKING SO WILL
CONTINUE WITH SLIGHT AND LOW CHANCE POPS BUT THESE MAY EVEN BE TOO
HIGH. WINDS WILL DIMINISH OVER LAND AREAS SUNDAY EVENING.

MONDAY THROUGH WEDNESDAY...THE COOL FRONTAL BOUNDARY WILL WEAKEN AND
WASH OUT TO THE SOUTH AND EAST OF THE AREA SUNDAY NIGHT INTO MONDAY
BUT STILL BE INTACT ENOUGH TO KEEP A BELT OF POOLED MOISTURE FROM
THE LOWER LAKES INTO CENTRAL ILLINOIS. THE ALASKAN UPPER WAVE WILL
DAMPEN BUT THE NORTHERN STREAM WILL BEGIN TO PHASE WITH THE
CALIFORNIA CUTOFF UPPER LOW. A LEAD SHORTWAVE WILL EJECT
NORTHEASTWARD FROM THE CENTRAL PLAINS AHEAD OF THE DEVELOPING
LONGWAVE TROUGH AXIS AND PUSH A WEAK SURFACE TROUGH ALONG THE OLD
FRONT/AREA OF POOLED MOISTURE MONDAY. THIS SHOULD PUSH THE MOISTURE
NORTHWARD AND BACK INTO MOST OF THE FORECAST AREA MONDAY MORNING.
THIS WILL SUPPORT INCREASED RAIN CHANCES...PRIMARILY ACROSS THE
SOUTHEAST TWO-THIRDS TO THREE-QUARTERS OF THE AREA MONDAY. THE
LARGER SCALE UPPER TROUGH WILL SWING ACROSS THE AREA AS IT AMPLIFIES
TUESDAY WITH ANOTHER SURFACE LOW MOVING FROM THE UPPER MISSISSIPPI
RIVER VALLEY INTO WESTERN ONTARIO. ANOTHER SHARP COLD FRONT WILL
CROSS THE AREA LATER TUESDAY AFTERNOON OR EARLY TUESDAY EVENING.
ANOTHER PERIOD OF GUSTY WINDS IS EXPECTED WITH THE STRONG COLD
ADVECTION AS H85 TEMPS FALL BACK TO THE -6 OR -8 C RANGE INTO
WEDNESDAY FROM THEIR ABOVE ZERO C READINGS PRIOR TO THAT.

THURSDAY AND FRIDAY...DRIER WEATHER WILL RETURN INTO THURSDAY AS
HIGH PRESSURE MOVES SOUTH OF THE AREA BUT THE UPPER FLOW PATTERN
WILL REMAIN ACTIVE JUST TO THE NORTH OF THE AREA. THEREFORE CANNOT
RULE OUT A WAVE MOVING CLOSE ENOUGH TO THE AREA TO KICK OFF SOME
SHOWERS ESPECIALLY AS WARM ADVECTION RETURNS THURSDAY NIGHT. THE
UPPER FLOW WILL TURN SOUTHWESTERLY SUGGESTING A RETURN TO MORE
ACTIVE WEATHER NEXT WEEKEND THOUGH WE SHOULD SEE AN UPSWING IN TEMPS
BY THAT TIME.

MDB

&&

.AVIATION...

//ORD AND MDW CONCERNS...UPDATED 15Z...

* SOUTH-SOUTHWEST WINDS GUSTING TO 20 TO 23 KT THIS AFTERNOON AND
POTENTIALLY TONIGHT.

* LOW LEVEL WIND SHEAR POTENTIAL TONIGHT.

* POTENTIAL FOR VERY GUSTY WINDS IN EXCESS OF 40 MPH ON SUNDAY.

//DISCUSSION...UPDATED 12Z...

GUSTY SOUTH-SOUTHWEST WINDS AND LOW LEVEL WIND SHEAR ARE THE MAIN
CONCERNS FOR TODAY AND TONIGHT.

WINDS WILL BE ON THE INCREASE THROUGH THE DAY AND ESPECIALLY
THE AFTERNOON HOURS AS DEEP LOW PRESSURE DROPS INTO THE NORTHERN
PLAINS STRENGTHENING THE SLY-SWLY GRADIENT OVER THE AREA. WITH
SKIES STARTING OUT SKC AND WITH ONLY INCREASING CI COVERAGE
THROUGH THE DAY...THERE SHOULD BE AMPLE OPPORTUNITY FOR GUSTS TO
ARND 20KT TO MIX DOWN TO THE SURFACE.

WINDS TONIGHT ARE A CONCERN AND CONTINUES TO BE A LOWER CONFIDENCE
FORECAST. THERE ARE SOME INDICATIONS THAT THERE COULD BE
INCREASING GUSTINESS THROUGH THE NIGHT AS STRONG WINDS OF 50-60KT
MOVE OVER THE AREA BEGINNING AT 1500-2000FT AGL. THE BIG CONCERN
REMAINS IN HOW MUCH OF A LOW LEVEL INVERSION MAY DEVELOP...WHICH
WOULD INHIBIT GUSTINESS. IF MID AND HIGH CLOUD IS NOT TOO
THICK...THEN THERE WOULD BE ENOUGH SFC COOLING TO ALLOW FOR A
STRONGER INVERSION THAN IS CLOUD COVER IS THICK...INHIBITING
RADIATIVE COOLING...LEADING TO A WEAKER INVERSION. HAVE TRENDED
CLOSER TO THE IDEA OF A WEAK INVERSION DEVELOPING...WITH SOME
GUSTINESS OVERNIGHT. HOWEVER...THIS WILL RAISE THE QUESTION OF LOW
LEVEL WIND SHEAR. WITH SFC WINDS ARND 15KT AND 50-60KT ABOVE AN
INVERSION AT 1.5-2.0KFT...SIGNIFICANT LLWS IS POSSIBLE.

THE NEXT CHANCE FOR ANY PCPN TO IMPACT THE TERMINALS WILL NOT
COME UNTIL SUNDAY MORNING AS A COLD FRONT APPROACHES THE REGION.
WILL CARRY A PROB30 FOR SHRA IN THE 24-30HR FORECAST PERIOD FOR
ORD. AT THAT TIME PERIOD...THERE SHOULD BE INCREASING PCPN CHANCES
AND WITH INCREASING LOW LEVEL MOISTURE RETURN...MVFR CIGS WILL BE
POSSIBLE.

//ORD AND MDW CONFIDENCE...UPDATED 15Z...

* HIGH CONFIDENCE IN WIND DIRECTION THROUGH THIS AFTERNOON WITH
MEDIUM CONFIDENCE IN WIND GUST SPEEDS THROUGH THIS AFTERNOON
AND TONIGHT.

* MEDIUM CONFIDENCE IN LLWS POTENTIAL TONIGHT.

* INCREASING CONFIDENCE FOR 40 MPH PLUS GUSTS ON SUNDAY.

//OUTLOOK FOR ORD/MDW FOR 00Z MONDAY-12Z SATURDAY...UPDATED 12Z...

SUNDAY NIGHT...VFR.

MONDAY...CHANCE SHRA. MVFR CIGS POSSIBLE.

TUESDAY THROUGH WEDNESDAY...VFR. WX NIL.

THURSDAY...VFR. SLIGHT CHANCE SHRA LATE.

FRIDAY...CHANCE SHRA AND MVFR CIGS.

KREIN/MTF

&&

.MARINE...

UPDATE...914 AM CST

OBSERVATIONS ACROSS THE NEAR SHORE ZONES AND NEARBY LAND
OBSERVATIONS INDICATE SOUTHWEST WIND SPEEDS ARE ON THE CLIMB
QUICKLY THIS MORNING. WITH 25 KT WINDS AT 2K FT AS SEEN ON LOCAL
RADAR LIKELY ABLE TO BE MIXED DOWN IN GUSTS...IT APPEARS SMALL
CRAFT ADVISORY CONDITIONS WILL BEGIN ENOUGH IN ADVANCE OF THE GALE
WARNING TO WARRANT THAT HEADLINE ISSUANCE. WILL BEGIN THE SMALL
CRAFT ADVISORY AT 3 PM.

MTF

300 AM CST

THROUGH THE NIGHT...WINDS HAVE BEEN DROPPING OFF AS LOW PRESSURE
OVER THE UPPER GREAT LAKES LIFTS TO THE NORTHEAST AND WEAKENS.
HOWEVER...WINDS WILL STRENGTHEN AGAIN LATER THIS AFTERNOON AND
EVENING AS LOW PRESSURE DROPS INTO THE NORTHERN PLAINS LATER
TODAY. SOUTH WINDS WILL QUICKLY INCREASE EARLY THIS EVENING TO
SOUTH GALES AS THE LOW RAPIDLY DEEPENS WHILE LIFTING NORTHEAST TO
HUDSON BAY. WINDS WILL BRIEFLY SUBSIDE BELOW GALE FORCE MONDAY
AND TUESDAY...BUT ANOTHER DEEP LOW IS EXPECTED TO DRAG A STRONG
COLD FRONT ACROSS THE LAKE TUESDAY EVENING. THE STRONG COLD
ADVECTION BEHIND THIS FRONT WILL USHER IN ANOTHER ROUND OF GALES
FOR TUESDAY NIGHT AND WEDNESDAY.

KREIN

&&

.LOT WATCHES/WARNINGS/ADVISORIES...
IL...NONE.
IN...NONE.
LM...GALE WARNING...LMZ080-LMZ261-LMZ362-LMZ364-LMZ366-LMZ563-LMZ565-
LMZ567-LMZ669-LMZ671-LMZ673-LMZ675-LMZ740-LMZ741-LMZ742-
LMZ743-LMZ744-LMZ745-LMZ777-LMZ779-LMZ868-LMZ870-LMZ872-
LMZ874-LMZ876-LMZ878...9 PM SATURDAY TO 9 PM SUNDAY.

&&

$$

Area Forecast Discussion 05:59:23.2134736

.DISCUSSION...
309 AM CST

AN ACTIVE FEW DAYS LAY AHEAD WITH THE MAIN FORECAST CONCERNS
CENTERED AROUND WINDS AND PRECIP CHANCES. EARLY MORNING WATER VAPOR
IMAGERY SHOWS A CORRIDOR OF FAIRLY FLAT UPPER FLOW OVER THE EASTERN
HALF OF THE COUNTRY WITH SLIGHT UPPER RIDGING TRANSLATING EASTWARD
ACROSS THE NORTHERN PLAINS AND UPPER MISSISSIPPI RIVER VALLEY. TO
THE WEST...A SERIES OF SHORTWAVES ARE LINED UP WITH ONE DIGGING INTO
WESTERN MONTANA AND ANOTHER MOVING ALONG THE SOUTHEASTERN ALASKAN
COAST TOWARD FAR NORTHERN BRITISH COLUMBIA. ANOTHER UPPER TROUGH IS
CUT OFF FROM THIS NORTHERN STREAM OF FLOW JUST OFF THE CALIFORNIA
COAST AND WILL PLAY A ROLE IN PRECIP CHANCES FOR OUR AREA EARLY NEXT
WEEK. AT THE SURFACE...LOW PRESSURE WAS OBSERVED JUST NORTHEAST OF
LAKE SUPERIOR. ANOTHER SURFACE LOW IS DEVELOPING OVER SOUTHERN
SASKATCHEWAN/CENTRAL MONTANA AS A RESULT OF THE AFOREMENTIONED UPPER
SHORTWAVE WITH A SUBTLE WARM FRONT/TROUGH ANALYZED FROM THE LOW
ARCHING SOUTHEASTWARD ACROSS NORTHERN ILLINOIS AND INDIANA. THIS LOW
WILL BE KEY IN BRINGING INCREASING WINDS TO THE REGION TONIGHT AND
SUNDAY.

TODAY...AM EXPECTING A MILDER DAY TODAY WITH WARM ADVECTION ONGOING
EARLY THIS MORNING. SOUTH WINDS WILL INCREASE EARLY THIS AFTERNOON
AND BECOME SOMEWHAT GUSTY AS THE PRESSURE GRADIENT TIGHTENS WITH THE
SURFACE LOW DEEPENING OVER THE NORTHERN PLAINS. MIXING TO BETWEEN
950 AND 925 MB IS EXPECTED TODAY RESULTING IN GUSTS AROUND 20 KT AT
TIMES AND HIGHS IN THE MID 50S NORTH TO UPPER 50S SOUTH OF
INTERSTATE 88...WITH A FEW AREAS POSSIBLY REACHING 60 DEGREES MAINLY
SOUTH OF INTERSTATE 80 THANKS TO THE BREEZY SOUTH-SOUTHWEST WINDS.

TONIGHT THROUGH SUNDAY NIGHT...THE SURFACE LOW WILL MOVE FROM
EASTERN NORTH DAKOTA INTO WESTERN ONTARIO TONIGHT WHILE DEEPENING
INTO THE 980-985 MB RANGE. WINDS AND TEMPS WILL BE TRICKY AS THEY
WILL BE DICTATED BY THE DECOUPLING OF THE BOUNDARY LAYER THIS
EVENING. AM THINKING THAT DECOUPLING MAY OCCUR WITH SUNSET LATE THIS
AFTERNOON ALLOWING GUSTS TO DIMINISH BUT THE TIGHTENING PRESSURE
GRADIENT WILL KEEP SUSTAINED WIND SPEEDS UP. THIS WOULD LEAD TO
LITTLE DROP OFF IN TEMPS THIS EVENING. A WEAK UPPER WAVE LOOKS TO
LIFT NORTHEASTWARD ACROSS THE AREA THIS EVENING BRINGING MODEST MID
LEVEL COOL ADVECTION FOR A SHORT TIME AND MAY SERVE AS A CATALYST
FOR MIXING TO RE-DEVELOP LEADING TO A RETURN OF WIND GUSTS. THE
CONCERN IS THAT THE LOW LEVEL JET RAMPS UP SIGNIFICANTLY THIS
EVENING WITH FORECAST SOUNDINGS INDICATING 30+ KT WINDS STARTING
AROUND 600 FT AGL AND 40+ KT WINDS AT 1000 FT WITH A PEAK AT AROUND
60 KT UP AROUND 2500 FT. ITS NOT OUT OF THE QUESTION THAT 30 KT
GUSTS COULD OCCUR OVERNIGHT. ANOTHER WARM FRONT LOOKS TO QUICKLY
CROSS THE AREA EARLY SUNDAY MORNING WITH A LOW LEVEL THERMAL AXIS
CRESTING THE AREA. WINDS BECOME A BIGGER ISSUE SUNDAY AS MIXING
COMMENCES. THE LOW WILL BE LIFTING NORTHEASTWARD TOWARDS SOUTHERN
HUDSON BAY AND LIKELY BE SOMEWHERE AROUND 980 MB. PEAK LOW LEVEL
WINDS DO SUBSIDE BUT A DEEP LAYER OF 40-50 KT WINDS CONTINUES INTO
EARLY SUNDAY AFTERNOON. MIXING SUPPORTS GUSTS TO NEAR 40 KT DURING
THE DAY WITH POTENTIAL FOR A BRIEF PERIOD OF HIGHER GUSTS OF 45 KT
OR POSSIBLY HIGHER AS THE COLD FRONT PASSES AROUND MIDDAY. PRECIP
CHANCES ARE NOT IMPRESSIVE WITH DEEP LAYER MOISTURE LACKING SO WILL
CONTINUE WITH SLIGHT AND LOW CHANCE POPS BUT THESE MAY EVEN BE TOO
HIGH. WINDS WILL DIMINISH OVER LAND AREAS SUNDAY EVENING.

MONDAY THROUGH WEDNESDAY...THE COOL FRONTAL BOUNDARY WILL WEAKEN AND
WASH OUT TO THE SOUTH AND EAST OF THE AREA SUNDAY NIGHT INTO MONDAY
BUT STILL BE INTACT ENOUGH TO KEEP A BELT OF POOLED MOISTURE FROM
THE LOWER LAKES INTO CENTRAL ILLINOIS. THE ALASKAN UPPER WAVE WILL
DAMPEN BUT THE NORTHERN STREAM WILL BEGIN TO PHASE WITH THE
CALIFORNIA CUTOFF UPPER LOW. A LEAD SHORTWAVE WILL EJECT
NORTHEASTWARD FROM THE CENTRAL PLAINS AHEAD OF THE DEVELOPING
LONGWAVE TROUGH AXIS AND PUSH A WEAK SURFACE TROUGH ALONG THE OLD
FRONT/AREA OF POOLED MOISTURE MONDAY. THIS SHOULD PUSH THE MOISTURE
NORTHWARD AND BACK INTO MOST OF THE FORECAST AREA MONDAY MORNING.
THIS WILL SUPPORT INCREASED RAIN CHANCES...PRIMARILY ACROSS THE
SOUTHEAST TWO-THIRDS TO THREE-QUARTERS OF THE AREA MONDAY. THE
LARGER SCALE UPPER TROUGH WILL SWING ACROSS THE AREA AS IT AMPLIFIES
TUESDAY WITH ANOTHER SURFACE LOW MOVING FROM THE UPPER MISSISSIPPI
RIVER VALLEY INTO WESTERN ONTARIO. ANOTHER SHARP COLD FRONT WILL
CROSS THE AREA LATER TUESDAY AFTERNOON OR EARLY TUESDAY EVENING.
ANOTHER PERIOD OF GUSTY WINDS IS EXPECTED WITH THE STRONG COLD
ADVECTION AS H85 TEMPS FALL BACK TO THE -6 OR -8 C RANGE INTO
WEDNESDAY FROM THEIR ABOVE ZERO C READINGS PRIOR TO THAT.

THURSDAY AND FRIDAY...DRIER WEATHER WILL RETURN INTO THURSDAY AS
HIGH PRESSURE MOVES SOUTH OF THE AREA BUT THE UPPER FLOW PATTERN
WILL REMAIN ACTIVE JUST TO THE NORTH OF THE AREA. THEREFORE CANNOT
RULE OUT A WAVE MOVING CLOSE ENOUGH TO THE AREA TO KICK OFF SOME
SHOWERS ESPECIALLY AS WARM ADVECTION RETURNS THURSDAY NIGHT. THE
UPPER FLOW WILL TURN SOUTHWESTERLY SUGGESTING A RETURN TO MORE
ACTIVE WEATHER NEXT WEEKEND THOUGH WE SHOULD SEE AN UPSWING IN TEMPS
BY THAT TIME.

MDB

&&

.AVIATION...

//ORD AND MDW CONCERNS...UPDATED 12Z...

* SOUTH-SOUTHWEST WINDS GUSTING TO AROUND 20KT TODAY.

* POTENTIAL FOR LOW LEVEL WIND SHEAR TONIGHT.

KREIN

//DISCUSSION...UPDATED 12Z...

GUSTY SOUTH-SOUTHWEST WINDS AND LOW LEVEL WIND SHEAR ARE THE MAIN
CONCERNS FOR TODAY AND TONIGHT.

WINDS WILL BE ON THE INCREASE THROUGH THE DAY AND ESPECIALLY
THE AFTERNOON HOURS AS DEEP LOW PRESSURE DROPS INTO THE NORTHERN
PLAINS STRENGTHENING THE SLY-SWLY GRADIENT OVER THE AREA. WITH
SKIES STARTING OUT SKC AND WITH ONLY INCREASING CI COVERAGE
THROUGH THE DAY...THERE SHOULD BE AMPLE OPPORTUNITY FOR GUSTS TO
ARND 20KT TO MIX DOWN TO THE SURFACE.

WINDS TONIGHT ARE A CONCERN AND CONTINUES TO BE A LOWER CONFIDENCE
FORECAST. THERE ARE SOME INDICATIONS THAT THERE COULD BE
INCREASING GUSTINESS THROUGH THE NIGHT AS STRONG WINDS OF 50-60KT
MOVE OVER THE AREA BEGINNING AT 1500-2000FT AGL. THE BIG CONCERN
REMAINS IN HOW MUCH OF A LOW LEVEL INVERSION MAY DEVELOP...WHICH
WOULD INHIBIT GUSTINESS. IF MID AND HIGH CLOUD IS NOT TOO
THICK...THEN THERE WOULD BE ENOUGH SFC COOLING TO ALLOW FOR A
STRONGER INVERSION THAN IS CLOUD COVER IS THICK...INHIBITING
RADIATIVE COOLING...LEADING TO A WEAKER INVERSION. HAVE TRENDED
CLOSER TO THE IDEA OF A WEAK INVERSION DEVELOPING...WITH SOME
GUSTINESS OVERNIGHT. HOWEVER...THIS WILL RAISE THE QUESTION OF LOW
LEVEL WIND SHEAR. WITH SFC WINDS ARND 15KT AND 50-60KT ABOVE AN
INVERSION AT 1.5-2.0KFT...SIGNIFICANT LLWS IS POSSIBLE.

THE NEXT CHANCE FOR ANY PCPN TO IMPACT THE TERMINALS WILL NOT
COME UNTIL SUNDAY MORNING AS A COLD FRONT APPROACHES THE REGION.
WILL CARRY A PROB30 FOR SHRA IN THE 24-30HR FORECAST PERIOD FOR
ORD. AT THAT TIME PERIOD...THERE SHOULD BE INCREASING PCPN CHANCES
AND WITH INCREASING LOW LEVEL MOISTURE RETURN...MVFR CIGS WILL BE
POSSIBLE.

KREIN

//ORD AND MDW CONFIDENCE...UPDATED 12Z...

* MEDIUM-HIGH CONFIDENCE IN WIND TRENDS THROUGH THIS EVENING.

* MEDIUM-HIGH CONFIDENCE IN LLWS POTENTIAL TONIGHT.

* MEDIUM CONFIDENCE IN WIND GUST MAGNITUDE TONIGHT.

* HIGH CONFIDENCE IN ALL OTHER FORECAST ELEMENTS.

KREIN

//OUTLOOK FOR ORD/MDW FOR 00Z MONDAY-12Z SATURDAY...UPDATED 12Z...

SUNDAY NIGHT...VFR.

MONDAY...CHANCE SHRA. MVFR CIGS POSSIBLE.

TUESDAY THROUGH WEDNESDAY...VFR. WX NIL.

THURSDAY...VFR. SLIGHT CHANCE SHRA LATE.

FRIDAY...CHANCE SHRA AND MVFR CIGS.

KREIN

&&

.MARINE...
300 AM CST

THROUGH THE NIGHT...WINDS HAVE BEEN DROPPING OFF AS LOW PRESSURE
OVER THE UPPER GREAT LAKES LIFTS TO THE NORTHEAST AND WEAKENS.
HOWEVER...WINDS WILL STRENGTHEN AGAIN LATER THIS AFTERNOON AND
EVENING AS LOW PRESSURE DROPS INTO THE NORTHERN PLAINS LATER
TODAY. SOUTH WINDS WILL QUICKLY INCREASE EARLY THIS EVENING TO
SOUTH GALES AS THE LOW RAPIDLY DEEPENS WHILE LIFTING NORTHEAST TO
HUDSON BAY. WINDS WILL BRIEFLY SUBSIDE BELOW GALE FORCE MONDAY
AND TUESDAY...BUT ANOTHER DEEP LOW IS EXPECTED TO DRAG A STRONG
COLD FRONT ACROSS THE LAKE TUESDAY EVENING. THE STRONG COLD
ADVECTION BEHIND THIS FRONT WILL USHER IN ANOTHER ROUND OF GALES
FOR TUESDAY NIGHT AND WEDNESDAY.

KREIN

&&

.LOT WATCHES/WARNINGS/ADVISORIES...
IL...NONE.
IN...NONE.
LM...GALE WARNING...LMZ080-LMZ261-LMZ362-LMZ364-LMZ366-LMZ563-LMZ565-
LMZ567-LMZ669-LMZ671-LMZ673-LMZ675-LMZ740-LMZ741-LMZ742-
LMZ743-LMZ744-LMZ745-LMZ777-LMZ779-LMZ868-LMZ870-LMZ872-
LMZ874-LMZ876-LMZ878...9 PM SATURDAY TO 9 PM SUNDAY.

&&

$$

Hazardous Weather Outlook 03:44:39.1334420

THIS HAZARDOUS WEATHER OUTLOOK IS FOR NORTH CENTRAL ILLINOIS...
NORTHEAST ILLINOIS AND NORTHWEST INDIANA.

.DAY ONE...TODAY AND TONIGHT.

NO HAZARDOUS WEATHER IS EXPECTED AT THIS TIME.

.DAYS TWO THROUGH SEVEN...SUNDAY THROUGH FRIDAY.

SOUTHWEST WINDS OF 20 TO 30 MPH WITH GUSTS AROUND 45 MPH ARE
POSSIBLE ON SUNDAY.

.SPOTTER INFORMATION STATEMENT...

SPOTTER ACTIVATION WILL NOT BE NECESSARY THROUGH TONIGHT.

&&

COMPLETE FORECAST INFORMATION IS AVAILABLE ON THE NWS CHICAGO
WEBPAGE: WEATHER.GOV/CHICAGO

Zone Forecast 03:38:11.1296008

.TODAY...SUNNY UNTIL LATE AFTERNOON THEN BECOMING PARTLY CLOUDY.
HIGHS IN THE MID 50S. SOUTH WINDS 15 TO 25 MPH. GUSTS UP TO
30 MPH LATE IN THE AFTERNOON.
.TONIGHT...MOSTLY CLOUDY. BREEZY. LOWS IN THE UPPER 40S. SOUTH
WINDS 15 TO 25 MPH WITH GUSTS UP TO 30 MPH AT TIMES.
.SUNDAY...WINDY. MOSTLY CLOUDY WITH A 20 PERCENT CHANCE OF LIGHT
SHOWERS. HIGHS IN THE MID 50S. SOUTHWEST WINDS 20 TO 30 MPH.
GUSTS UP TO 30 MPH EARLY IN THE MORNING INCREASING TO 45 MPH IN
THE LATE MORNING AND AFTERNOON.
.SUNDAY NIGHT...PARTLY CLOUDY. LOWS IN THE UPPER 30S. SOUTHWEST
WINDS 10 TO 15 MPH. GUSTS UP TO 30 MPH IN THE EVENING.
.MONDAY...PARTLY SUNNY WITH A 30 PERCENT CHANCE OF SHOWERS. HIGHS
IN THE LOWER 50S. SOUTH WINDS 10 TO 15 MPH.
.MONDAY NIGHT...PARTLY CLOUDY. LOWS IN THE UPPER 30S.
.TUESDAY...PARTLY CLOUDY. HIGHS IN THE LOWER 50S.
.TUESDAY NIGHT...MOSTLY CLEAR. LOWS AROUND 30.
.WEDNESDAY THROUGH THURSDAY NIGHT...PARTLY CLOUDY. HIGHS IN THE
LOWER 40S. LOWS AROUND 30.
.FRIDAY...PARTLY SUNNY WITH A 20 PERCENT CHANCE OF RAIN. HIGHS
AROUND 50.

Area Forecast Discussion 03:14:55.1157805

.DISCUSSION...
309 AM CST

AN ACTIVE FEW DAYS LAY AHEAD WITH THE MAIN FORECAST CONCERNS
CENTERED AROUND WINDS AND PRECIP CHANCES. EARLY MORNING WATER VAPOR
IMAGERY SHOWS A CORRIDOR OF FAIRLY FLAT UPPER FLOW OVER THE EASTERN
HALF OF THE COUNTRY WITH SLIGHT UPPER RIDGING TRANSLATING EASTWARD
ACROSS THE NORTHERN PLAINS AND UPPER MISSISSIPPI RIVER VALLEY. TO
THE WEST...A SERIES OF SHORTWAVES ARE LINED UP WITH ONE DIGGING INTO
WESTERN MONTANA AND ANOTHER MOVING ALONG THE SOUTHEASTERN ALASKAN
COAST TOWARD FAR NORTHERN BRITISH COLUMBIA. ANOTHER UPPER TROUGH IS
CUT OFF FROM THIS NORTHERN STREAM OF FLOW JUST OFF THE CALIFORNIA
COAST AND WILL PLAY A ROLE IN PRECIP CHANCES FOR OUR AREA EARLY NEXT
WEEK. AT THE SURFACE...LOW PRESSURE WAS OBSERVED JUST NORTHEAST OF
LAKE SUPERIOR. ANOTHER SURFACE LOW IS DEVELOPING OVER SOUTHERN
SASKATCHEWAN/CENTRAL MONTANA AS A RESULT OF THE AFOREMENTIONED UPPER
SHORTWAVE WITH A SUBTLE WARM FRONT/TROUGH ANALYZED FROM THE LOW
ARCHING SOUTHEASTWARD ACROSS NORTHERN ILLINOIS AND INDIANA. THIS LOW
WILL BE KEY IN BRINGING INCREASING WINDS TO THE REGION TONIGHT AND
SUNDAY.

TODAY...AM EXPECTING A MILDER DAY TODAY WITH WARM ADVECTION ONGOING
EARLY THIS MORNING. SOUTH WINDS WILL INCREASE EARLY THIS AFTERNOON
AND BECOME SOMEWHAT GUSTY AS THE PRESSURE GRADIENT TIGHTENS WITH THE
SURFACE LOW DEEPENING OVER THE NORTHERN PLAINS. MIXING TO BETWEEN
950 AND 925 MB IS EXPECTED TODAY RESULTING IN GUSTS AROUND 20 KT AT
TIMES AND HIGHS IN THE MID 50S NORTH TO UPPER 50S SOUTH OF
INTERSTATE 88...WITH A FEW AREAS POSSIBLY REACHING 60 DEGREES MAINLY
SOUTH OF INTERSTATE 80 THANKS TO THE BREEZY SOUTH-SOUTHWEST WINDS.

TONIGHT THROUGH SUNDAY NIGHT...THE SURFACE LOW WILL MOVE FROM
EASTERN NORTH DAKOTA INTO WESTERN ONTARIO TONIGHT WHILE DEEPENING
INTO THE 980-985 MB RANGE. WINDS AND TEMPS WILL BE TRICKY AS THEY
WILL BE DICTATED BY THE DECOUPLING OF THE BOUNDARY LAYER THIS
EVENING. AM THINKING THAT DECOUPLING MAY OCCUR WITH SUNSET LATE THIS
AFTERNOON ALLOWING GUSTS TO DIMINISH BUT THE TIGHTENING PRESSURE
GRADIENT WILL KEEP SUSTAINED WIND SPEEDS UP. THIS WOULD LEAD TO
LITTLE DROP OFF IN TEMPS THIS EVENING. A WEAK UPPER WAVE LOOKS TO
LIFT NORTHEASTWARD ACROSS THE AREA THIS EVENING BRINGING MODEST MID
LEVEL COOL ADVECTION FOR A SHORT TIME AND MAY SERVE AS A CATALYST
FOR MIXING TO RE-DEVELOP LEADING TO A RETURN OF WIND GUSTS. THE
CONCERN IS THAT THE LOW LEVEL JET RAMPS UP SIGNIFICANTLY THIS
EVENING WITH FORECAST SOUNDINGS INDICATING 30+ KT WINDS STARTING
AROUND 600 FT AGL AND 40+ KT WINDS AT 1000 FT WITH A PEAK AT AROUND
60 KT UP AROUND 2500 FT. ITS NOT OUT OF THE QUESTION THAT 30 KT
GUSTS COULD OCCUR OVERNIGHT. ANOTHER WARM FRONT LOOKS TO QUICKLY
CROSS THE AREA EARLY SUNDAY MORNING WITH A LOW LEVEL THERMAL AXIS
CRESTING THE AREA. WINDS BECOME A BIGGER ISSUE SUNDAY AS MIXING
COMMENCES. THE LOW WILL BE LIFTING NORTHEASTWARD TOWARDS SOUTHERN
HUDSON BAY AND LIKELY BE SOMEWHERE AROUND 980 MB. PEAK LOW LEVEL
WINDS DO SUBSIDE BUT A DEEP LAYER OF 40-50 KT WINDS CONTINUES INTO
EARLY SUNDAY AFTERNOON. MIXING SUPPORTS GUSTS TO NEAR 40 KT DURING
THE DAY WITH POTENTIAL FOR A BRIEF PERIOD OF HIGHER GUSTS OF 45 KT
OR POSSIBLY HIGHER AS THE COLD FRONT PASSES AROUND MIDDAY. PRECIP
CHANCES ARE NOT IMPRESSIVE WITH DEEP LAYER MOISTURE LACKING SO WILL
CONTINUE WITH SLIGHT AND LOW CHANCE POPS BUT THESE MAY EVEN BE TOO
HIGH. WINDS WILL DIMINISH OVER LAND AREAS SUNDAY EVENING.

MONDAY THROUGH WEDNESDAY...THE COOL FRONTAL BOUNDARY WILL WEAKEN AND
WASH OUT TO THE SOUTH AND EAST OF THE AREA SUNDAY NIGHT INTO MONDAY
BUT STILL BE INTACT ENOUGH TO KEEP A BELT OF POOLED MOISTURE FROM
THE LOWER LAKES INTO CENTRAL ILLINOIS. THE ALASKAN UPPER WAVE WILL
DAMPEN BUT THE NORTHERN STREAM WILL BEGIN TO PHASE WITH THE
CALIFORNIA CUTOFF UPPER LOW. A LEAD SHORTWAVE WILL EJECT
NORTHEASTWARD FROM THE CENTRAL PLAINS AHEAD OF THE DEVELOPING
LONGWAVE TROUGH AXIS AND PUSH A WEAK SURFACE TROUGH ALONG THE OLD
FRONT/AREA OF POOLED MOISTURE MONDAY. THIS SHOULD PUSH THE MOISTURE
NORTHWARD AND BACK INTO MOST OF THE FORECAST AREA MONDAY MORNING.
THIS WILL SUPPORT INCREASED RAIN CHANCES...PRIMARILY ACROSS THE
SOUTHEAST TWO-THIRDS TO THREE-QUARTERS OF THE AREA MONDAY. THE
LARGER SCALE UPPER TROUGH WILL SWING ACROSS THE AREA AS IT AMPLIFIES
TUESDAY WITH ANOTHER SURFACE LOW MOVING FROM THE UPPER MISSISSIPPI
RIVER VALLEY INTO WESTERN ONTARIO. ANOTHER SHARP COLD FRONT WILL
CROSS THE AREA LATER TUESDAY AFTERNOON OR EARLY TUESDAY EVENING.
ANOTHER PERIOD OF GUSTY WINDS IS EXPECTED WITH THE STRONG COLD
ADVECTION AS H85 TEMPS FALL BACK TO THE -6 OR -8 C RANGE INTO
WEDNESDAY FROM THEIR ABOVE ZERO C READINGS PRIOR TO THAT.

THURSDAY AND FRIDAY...DRIER WEATHER WILL RETURN INTO THURSDAY AS
HIGH PRESSURE MOVES SOUTH OF THE AREA BUT THE UPPER FLOW PATTERN
WILL REMAIN ACTIVE JUST TO THE NORTH OF THE AREA. THEREFORE CANNOT
RULE OUT A WAVE MOVING CLOSE ENOUGH TO THE AREA TO KICK OFF SOME
SHOWERS ESPECIALLY AS WARM ADVECTION RETURNS THURSDAY NIGHT. THE
UPPER FLOW WILL TURN SOUTHWESTERLY SUGGESTING A RETURN TO MORE
ACTIVE WEATHER NEXT WEEKEND THOUGH WE SHOULD SEE AN UPSWING IN TEMPS
BY THAT TIME.

MDB

&&

.AVIATION...

//ORD AND MDW CONCERNS...UPDATED 09Z...

* SOUTH-SOUTHWEST WINDS GUSTING TO AROUND 20KT TODAY.

* POTENTIAL FOR WIND GUSTS IN EXCESS OF 25 KT TONIGHT.

KREIN

//DISCUSSION...UPDATED 06Z...

GUSTY SOUTH-SOUTHWEST WINDS ARE THE MAIN CONCERN THROUGH THE
CURRENT TAF PERIOD.

WARM FRONTAL TROUGH HAS BECOME LESS WELL-DEFINED AS IT LIFTS
NORTHEAST ACROSS THE AREA THIS EVENING. THIS...COMBINED WITH
DIURNAL LOSS OF LOW LEVEL MIXING HAS ALLOWED WINDS TO DIMINISH TO
LESS THAN 10 KTS...AND BACK TO THE SOUTH-SOUTHWEST. LIGHT
SOUTHWEST WINDS WILL PREVAIL OVERNIGHT...ALONG WITH VFR
CONDITIONS WITH MAINLY CLEAR SKIES.

WINDS WILL INCREASE ON SATURDAY...ESPECIALLY DURING THE AFTERNOON
HOURS AS DEEP LOW PRESSURE DEVELOPS OVER THE NORTHERN PLAINS.
SURFACE PRESSURE FALLS AND TIGHTENING OF THE PRESSURE GRADIENT
ACROSS THE MIDWEST WILL LIKELY RESULT SOUTHWEST WINDS GUSTING
ABOVE 20 KTS BY MID/LATE AFTERNOON. VRF HIGH CLOUD COVER WILL
INCREASE AND THICKEN DURING THE AFTERNOON...WHICH MAY TEND TO
LIMIT LOW LEVEL MIXING SOMEWHAT.

CONFIDENCE DECREASES IN THE WIND FORECAST SATURDAY EVENING.
THE GRADIENT CONTINUES TO TIGHTEN AS LOW DEEPENS ACROSS THE UPPER
MIDWEST AND SOUTHERN MANITOBA...WHICH IS EXPECTED TO INCREASE
SUSTAINED SPEEDS DURING THE EVENING AND OVERNIGHT HOURS. THE BIG
QUESTION IS HOW GUSTY WINDS WILL BE...AS NOCTURNAL INVERSION
ATTEMPTS TO DEVELOP WITH SUNSET. FORECAST SOUNDINGS INDICATE
CONSIDERABLE MOMENTUM ABOVE THE BOUNDARY LAYER...WITH WINDS
INCREASING TO AROUND 50 KTS AT THE 1500-2000 FT LEVEL. WOULD
SUSPECT THAT GUSTS WILL REMAIN A FACTOR AS BOUNDARY LAYER ATTEMPTS
TO STABILIZE...THUS HAVE INCREASED GUSTS AFTER DARK TO THE 25-30
KT RANGE. GIVEN THE MOMENTUM NOT TOO FAR ABOVE THE SURFACE...
COULD SEE SPORADIC HIGHER GUSTS. MID AND HIGH CLOUD COVER EXPECTED
TO REMAIN VFR...THOUGH POTENTIAL FOR LOWER CIGS AND SPOTTY SHRA
DOES INCREASE TOWARD SUNDAY MORNING ESPECIALLY JUST BEYOND ORD 30
HOUR FORECAST AT THIS TIME.

RATZER

//ORD AND MDW CONFIDENCE...UPDATED 09Z...

* MEDIUM-HIGH CONFIDENCE IN WIND TRENDS THROUGH THIS AFTERNOON.

* MEDIUM CONFIDENCE IN WIND GUST MAGNITUDE TONIGHT.

KREIN

//OUTLOOK FOR ORD/MDW FOR 12Z SUNDAY-12Z FRIDAY...UPDATED 00Z...

SUNDAY...CHANCE SHRA AND MVFR CIGS EARLY. WINDY. SWLY GUSTS TO 35
KT IN THE AFTERNOON.

MONDAY...CHANCE SHRA. MVFR CIGS POSSIBLE.

TUESDAY THROUGH THURSDAY...VFR.

RATZER

&&

.MARINE...
300 AM CST

THROUGH THE NIGHT...WINDS HAVE BEEN DROPPING OFF AS LOW PRESSURE
OVER THE UPPER GREAT LAKES LIFTS TO THE NORTHEAST AND WEAKENS.
HOWEVER...WINDS WILL STRENGTHEN AGAIN LATER THIS AFTERNOON AND
EVENING AS LOW PRESSURE DROPS INTO THE NORTHERN PLAINS LATER
TODAY. SOUTH WINDS WILL QUICKLY INCREASE EARLY THIS EVENING TO
SOUTH GALES AS THE LOW RAPIDLY DEEPENS WHILE LIFTING NORTHEAST TO
HUDSON BAY. WINDS WILL BRIEFLY SUBSIDE BELOW GALE FORCE MONDAY
AND TUESDAY...BUT ANOTHER DEEP LOW IS EXPECTED TO DRAG A STRONG
COLD FRONT ACROSS THE LAKE TUESDAY EVENING. THE STRONG COLD
ADVECTION BEHIND THIS FRONT WILL USHER IN ANOTHER ROUND OF GALES
FOR TUESDAY NIGHT AND WEDNESDAY.

KREIN

&&

.LOT WATCHES/WARNINGS/ADVISORIES...
IL...NONE.
IN...NONE.
LM...GALE WARNING...LMZ080-LMZ261-LMZ362-LMZ364-LMZ366-LMZ563-LMZ565-
LMZ567-LMZ669-LMZ671-LMZ673-LMZ675-LMZ740-LMZ741-LMZ742-
LMZ743-LMZ744-LMZ745-LMZ777-LMZ779-LMZ868-LMZ870-LMZ872-
LMZ874-LMZ876-LMZ878...9 PM SATURDAY TO 9 PM SUNDAY.

&&

$$

Area Forecast Discussion 23:03:20.8217000

.DISCUSSION...
330 PM CST

THE MAIN ISSUES DURING THE FORECAST PERIOD WILL BE WINDS ON SUNDAY
AND PRECIPITATION AMOUNTS MONDAY AND MONDAY NIGHT.

THE MODELS AND ENSEMBLES STILL INDICATE SOME UNCERTAINTY WITH THE
THE EVOLUTION OF THE UPPER LOW OFF THE CALIFORNIA COAST. HOWEVER...THE
MODELS ARE BEGINNING TO AGREE THAT A MAJORITY OF THE ENERGY
ASSOCIATED WITH THIS SYSTEM WILL REMAIN SOUTH OF NORTHERN ILLINOIS.

THE LATEST OBJECTIVE SURFACE ANALYSIS PLACES A WARM FRONT WEST AND
SOUTH OF MY CWA THIS AFTERNOON. THIS FRONT WILL PUSH ACROSS NORTHERN
ILLINOIS THIS EVENING...SETTING UP A DECENT WARMING TREND ON
SATURDAY. SOUTHWESTERLY WINDS DURING THE DAY ON SATURDAY WILL ALLOW
TEMPERATURES TO WARM INTO THE 50S AREA WIDE.

THE MAIN ATTENTION THIS AFTERNOON IS FOCUSED ON SUNDAY AS A
COMPLEX NORTHERN STREAM SHORT WAVE...EMANATING FROM THE
NORTHEASTERN PACIFIC...IS EXPECTED TO PUSH ACROSS THE UPPER
MISSISSIPPI RIVER VALLEY. THIS POTENT SHORT WAVE WILL DRIVE A
STRONG SURFACE LOW ACROSS THE FAR NORTHERN STATES AND SOUTHERN
CANADA. SOUTH TO SOUTHWESTERLY WINDS AHEAD OF THIS LOW LOOK TO
INCREASE ACROSS MUCH OF THE GREAT LAKES REGION AS THIS SUB 985 MB
LOW PUSHES EASTWARD INTO WESTERN ONTARIO. IN FACT IT APPEARS THAT
A WIND ADVISORY MAY BE NEEDED FOR SUNDAY AS STRONG ISALLOBARIC
PRESSURE RISES LOOK TO COUPLE WITH DECENT COLD AIR ADVECTION
BEHIND THE SURFACE COLD FRONT SUNDAY AFTERNOON AND EVENING. MODEL
GUIDANCE ALSO SUGGESTS THAT MEAN BOUNDARY LAYER WINDS COULD EXCEED
40 KT SUNDAY AFTERNOON...AND WITH STRONG SYNOPTIC SCALE DECENT
EXPECTED IN THE WAKE OF THE UPPER LEVEL SHORT WAVE IT WOULD NOT BE
HARD TO GET 40+ KT GUSTS TO THE SURFACE. I WILL HIGHLIGHT THIS
THREAT IN THE HWO FOR NOW AS IT IS WAY TO EARLY FOR A WIND
ADVISORY.

THE OTHER CONCERN WILL BE THE THREAT FOR RAINFALL EARLY NEXT WEEK AS
ADDITIONAL NORTHERN STREAM ENERGY DIGS SOUTHEASTWARD THROUGH THE
LARGER SCALE TROUGH. THIS APPEARS TO BE SETTING UP SOME RAINFALL
FOR PORTIONS OF THE AREA ON MONDAY. HOWEVER...THE HEAVIEST RAINFALL
NOW APPEARS THAT IT WILL FALL FARTHER SOUTH ACROSS CENTRAL AND
SOUTHERN INDIANA MONDAY NIGHT INTO TUESDAY AS THE MAIN SOUTHERN
STREAM ENERGY EJECTS EASTWARD ACROSS THE LOWER MISSISSIPPI VALLEY.

FOLLOWING THIS SYSTEM...THE LARGE SCALE TROUGH WILL SHIFT EASTWARD
AND SET UP A QUASI ZONAL FLOW PATTERN ACROSS THE CONUS FOR THE
MIDDLE PART OF NEXT WEEK. OVERALL THIS WILL LEAD TO A COOL BUT DRY
WEATHER PATTERN FOR A FEW DAYS NEXT WEEK. HOWEVER...IT APPEARS THAT
THE WEATHER PATTERN MAY BECOME ACTIVE AGAIN BY THE LATER PART OF
NEXT WEEK AS POSITIVE HEIGHT ANOMALIES BUILD ACROSS THE NORTHERN
PACIFIC AND DRIVE A STRONG TROUGH FROM ALASKA SOUTHEASTWARD ACROSS
WESTERN NORTH AMERICA. THIS FLOW PATTERN LOOKS TO SET UP POSITIVE
HEIGHT ANOMALIES ACROSS THE SOUTHEASTERN CONUS AND HENCE SOUTHWEST
FLOW ALOFT ACROSS THE CENTRAL PORTION OF THE COUNTY. THIS
ATMOSPHERIC FLOW PATTERN MAY RESULT IN A WARM AND WETTER WEATHER
PATTERN INTO NEXT WEEKEND.

KJB

&&

.AVIATION...

//ORD AND MDW CONCERNS...UPDATED 06Z...

* SOUTH-SOUTHWEST WINDS INCREASING SATURDAY.

* POTENTIAL FOR WIND GUSTS IN EXCESS OF 25 KT SATURDAY NIGHT.

RATZER

//DISCUSSION...UPDATED 06Z...

GUSTY SOUTH-SOUTHWEST WINDS ARE THE MAIN CONCERN THROUGH THE
CURRENT TAF PERIOD.

WARM FRONTAL TROUGH HAS BECOME LESS WELL-DEFINED AS IT LIFTS
NORTHEAST ACROSS THE AREA THIS EVENING. THIS...COMBINED WITH
DIURNAL LOSS OF LOW LEVEL MIXING HAS ALLOWED WINDS TO DIMINISH TO
LESS THAN 10 KTS...AND BACK TO THE SOUTH-SOUTHWEST. LIGHT
SOUTHWEST WINDS WILL PREVAIL OVERNIGHT...ALONG WITH VFR
CONDITIONS WITH MAINLY CLEAR SKIES.

WINDS WILL INCREASE ON SATURDAY...ESPECIALLY DURING THE AFTERNOON
HOURS AS DEEP LOW PRESSURE DEVELOPS OVER THE NORTHERN PLAINS.
SURFACE PRESSURE FALLS AND TIGHTENING OF THE PRESSURE GRADIENT
ACROSS THE MIDWEST WILL LIKELY RESULT SOUTHWEST WINDS GUSTING
ABOVE 20 KTS BY MID/LATE AFTERNOON. VRF HIGH CLOUD COVER WILL
INCREASE AND THICKEN DURING THE AFTERNOON...WHICH MAY TEND TO
LIMIT LOW LEVEL MIXING SOMEWHAT.

CONFIDENCE DECREASES IN THE WIND FORECAST SATURDAY EVENING.
THE GRADIENT CONTINUES TO TIGHTEN AS LOW DEEPENS ACROSS THE UPPER
MIDWEST AND SOUTHERN MANITOBA...WHICH IS EXPECTED TO INCREASE
SUSTAINED SPEEDS DURING THE EVENING AND OVERNIGHT HOURS. THE BIG
QUESTION IS HOW GUSTY WINDS WILL BE...AS NOCTURNAL INVERSION
ATTEMPTS TO DEVELOP WITH SUNSET. FORECAST SOUNDINGS INDICATE
CONSIDERABLE MOMENTUM ABOVE THE BOUNDARY LAYER...WITH WINDS
INCREASING TO AROUND 50 KTS AT THE 1500-2000 FT LEVEL. WOULD
SUSPECT THAT GUSTS WILL REMAIN A FACTOR AS BOUNDARY LAYER ATTEMPTS
TO STABILIZE...THUS HAVE INCREASED GUSTS AFTER DARK TO THE 25-30
KT RANGE. GIVEN THE MOMENTUM NOT TOO FAR ABOVE THE SURFACE...
COULD SEE SPORADIC HIGHER GUSTS. MID AND HIGH CLOUD COVER EXPECTED
TO REMAIN VFR...THOUGH POTENTIAL FOR LOWER CIGS AND SPOTTY SHRA
DOES INCREASE TOWARD SUNDAY MORNING ESPECIALLY JUST BEYOND ORD 30
HOUR FORECAST AT THIS TIME.

RATZER

//ORD AND MDW CONFIDENCE...UPDATED 06Z...

* HIGH CONFIDENCE ALL ELEMENTS THROUGH SATURDAY MORNING.

* MEDIUM-HIGH CONFIDENCE IN WIND TRENDS THROUGH SATURDAY
AFTERNOON.

* MEDIUM CONFIDENCE IN WIND GUST MAGNITUDE SATURDAY NIGHT.

RATZER

//OUTLOOK FOR ORD/MDW FOR 12Z SUNDAY-12Z FRIDAY...UPDATED 00Z...

SUNDAY...CHANCE SHRA AND MVFR CIGS EARLY. WINDY. SWLY GUSTS TO 35
KT IN THE AFTERNOON.

MONDAY...CHANCE SHRA. MVFR CIGS POSSIBLE.

TUESDAY THROUGH THURSDAY...VFR.

RATZER

&&

.MARINE...
357 PM CST

WIND GUSTS HAVE BEEN SLOW TO DEVELOP TODAY DUE TO LINGERING CLOUD
COVER THAT IS INHIBITING MIXING. WITH THE COMBINATION OF LITTLE
CLOUD COVER AND COLD AIR ABOVE THE WARM LAKE...STILL EXPECTING GUSTS
TO 30 KT OVER THE SOUTHERN HALF OF THE LAKE AND GALES UP TO 35 KT
OVER THE NORTHERN HALF OF THE LAKE. SOUTHWEST FLOW CONTINUES
TOMORROW WITH GUSTS UP TO 25 KT AND INCREASING CLOUDS THROUGH THE
DAY. A DEEPENING LOW PASSES NORTH OF THE GREAT LAKES ON SUNDAY
BRINGING STRONG PRESSURE RISES BEHIND THE LOW AND CAA BEHIND THE
FRONT...GALES UP TO 45 KT ARE EXPECTED ESPECIALLY OVER THE NORTHERN
HALF OF THE LAKE. MODELS HAVE INDICATED DEEP MIXING WITH GUSTS
RANGING BETWEEN 45 AND 64 KT ACROSS THE NORTHERN HALF OF THE LAKE.
DECIDED TO STAY BELOW STORM FORCE WIND SPEEDS FOR NOW DUE TO THE
UNCERTAINTY BETWEEN THE MODELS. THAT BEING SAID...IF MODELS
CONTINUE TO SHOW POSSIBILITIES OF STORM FORCE WINDS...THE GALE WATCH
MAY BE UPGRADED TO A STORM WATCH OR WARNING.

AFTER THE SUNDAY HIGH END GALES...WINDS WILL STAY ELEVATED OUT OF
THE SOUTHWEST MONDAY INTO EARLY TUESDAY...WITH MAXIMUM WINDS IN THE
20 TO 30 KT RANGE. THEN YET ANOTHER DEEP LOW WILL MOVE NORTH OF
THE LAKE ON TUESDAY...TIGHTENING THE PRESSURE GRADIENT AND STEADILY
RAMPING WEST-SOUTHWEST WINDS UP THROUGH THE AFTERNOON. LOW END GALES
ARE POSSIBLE BY THE LATE AFTERNOON...ESPECIALLY FOR THE SOUTH HALF.
AFTER COLD FRONT PASSAGE TUESDAY EVENING...WINDS WILL TURN
WEST-NORTHWEST AND COLD AIR PUSHING ACROSS THE LAKE WILL MAKE FOR AN
UNSTABLE SET-UP AND PROLONG POSSIBLE GALES ACROSS THE ENTIRE
LAKE THROUGH TUESDAY NIGHT. HIGH PRESSURE WILL APPROACH FROM THE MID
MISSISSIPPI VALLEY LATE TUESDAY NIGHT...CAUSING WINDS TO DIMINISH
SOMEWHAT FOR THE SOUTH HALF OF THE LAKE ON WEDNESDAY...BUT THE
NORTH HALF WILL MAINTAIN A STRONGER PRESSURE GRADIENT AND BE SLOWER
TO COME DOWN.

JEE/RC

&&

.LOT WATCHES/WARNINGS/ADVISORIES...
IL...NONE.
IN...NONE.
LM...GALE WARNING...LMZ261-LMZ362-LMZ364-LMZ366-LMZ563-LMZ565-LMZ567-
LMZ868 UNTIL 2 AM SATURDAY.

GALE WATCH...LMZ080-LMZ261-LMZ362-LMZ364-LMZ366-LMZ563-LMZ565-
LMZ567-LMZ669-LMZ671-LMZ673-LMZ675-LMZ777-LMZ779-LMZ868-
LMZ870-LMZ872-LMZ874-LMZ876-LMZ878...6 AM SUNDAY TO
MIDNIGHT MONDAY.

SMALL CRAFT ADVISORY...NEARSHORE WATERS
UNTIL 3 AM SATURDAY.

GALE WATCH...LMZ740-LMZ741-LMZ742-LMZ743-LMZ744-LMZ745...9 AM
SUNDAY TO 9 PM SUNDAY.

&&

$$

Zone Forecast 21:54:58.7810902

.REST OF TONIGHT...CLEAR. LOWS IN THE LOWER 30S. SOUTHWEST WINDS
5 TO 10 MPH.
.SATURDAY...MOSTLY SUNNY. HIGHS IN THE MID 50S. SOUTH WINDS 10 TO
15 MPH.
.SATURDAY NIGHT...MOSTLY CLOUDY. TEMPERATURES NEARLY STEADY IN
THE UPPER 40S. SOUTH WINDS 10 TO 20 MPH.
.SUNDAY...WINDY. MOSTLY CLOUDY WITH A 20 PERCENT CHANCE OF LIGHT
SHOWERS. HIGHS IN THE UPPER 50S. SOUTHWEST WINDS 20 TO 30 MPH
WITH GUSTS UP TO 45 MPH AT TIMES.
.SUNDAY NIGHT...PARTLY CLOUDY. LOWS IN THE UPPER 30S. SOUTHWEST
WINDS 10 TO 15 MPH.
.MONDAY...PARTLY SUNNY WITH A 30 PERCENT CHANCE OF SHOWERS. HIGHS
IN THE LOWER 50S.
.MONDAY NIGHT...PARTLY CLOUDY WITH A 20 PERCENT CHANCE OF
SHOWERS. LOWS IN THE UPPER 30S.
.TUESDAY...PARTLY CLOUDY. HIGHS IN THE LOWER 50S.
.TUESDAY NIGHT THROUGH THURSDAY NIGHT...PARTLY CLOUDY. LOWS
AROUND 30. HIGHS IN THE MID 40S.
.FRIDAY...PARTLY SUNNY WITH A 20 PERCENT CHANCE OF RAIN. HIGHS IN
THE UPPER 40S.

Area Forecast Discussion 21:05:49.7518951

.DISCUSSION...
330 PM CST

THE MAIN ISSUES DURING THE FORECAST PERIOD WILL BE WINDS ON SUNDAY
AND PRECIPITATION AMOUNTS MONDAY AND MONDAY NIGHT.

THE MODELS AND ENSEMBLES STILL INDICATE SOME UNCERTAINTY WITH THE
THE EVOLUTION OF THE UPPER LOW OFF THE CALIFORNIA COAST. HOWEVER...THE
MODELS ARE BEGINNING TO AGREE THAT A MAJORITY OF THE ENERGY
ASSOCIATED WITH THIS SYSTEM WILL REMAIN SOUTH OF NORTHERN ILLINOIS.

THE LATEST OBJECTIVE SURFACE ANALYSIS PLACES A WARM FRONT WEST AND
SOUTH OF MY CWA THIS AFTERNOON. THIS FRONT WILL PUSH ACROSS NORTHERN
ILLINOIS THIS EVENING...SETTING UP A DECENT WARMING TREND ON
SATURDAY. SOUTHWESTERLY WINDS DURING THE DAY ON SATURDAY WILL ALLOW
TEMPERATURES TO WARM INTO THE 50S AREA WIDE.

THE MAIN ATTENTION THIS AFTERNOON IS FOCUSED ON SUNDAY AS A
COMPLEX NORTHERN STREAM SHORT WAVE...EMANATING FROM THE
NORTHEASTERN PACIFIC...IS EXPECTED TO PUSH ACROSS THE UPPER
MISSISSIPPI RIVER VALLEY. THIS POTENT SHORT WAVE WILL DRIVE A
STRONG SURFACE LOW ACROSS THE FAR NORTHERN STATES AND SOUTHERN
CANADA. SOUTH TO SOUTHWESTERLY WINDS AHEAD OF THIS LOW LOOK TO
INCREASE ACROSS MUCH OF THE GREAT LAKES REGION AS THIS SUB 985 MB
LOW PUSHES EASTWARD INTO WESTERN ONTARIO. IN FACT IT APPEARS THAT
A WIND ADVISORY MAY BE NEEDED FOR SUNDAY AS STRONG ISALLOBARIC
PRESSURE RISES LOOK TO COUPLE WITH DECENT COLD AIR ADVECTION
BEHIND THE SURFACE COLD FRONT SUNDAY AFTERNOON AND EVENING. MODEL
GUIDANCE ALSO SUGGESTS THAT MEAN BOUNDARY LAYER WINDS COULD EXCEED
40 KT SUNDAY AFTERNOON...AND WITH STRONG SYNOPTIC SCALE DECENT
EXPECTED IN THE WAKE OF THE UPPER LEVEL SHORT WAVE IT WOULD NOT BE
HARD TO GET 40+ KT GUSTS TO THE SURFACE. I WILL HIGHLIGHT THIS
THREAT IN THE HWO FOR NOW AS IT IS WAY TO EARLY FOR A WIND
ADVISORY.

THE OTHER CONCERN WILL BE THE THREAT FOR RAINFALL EARLY NEXT WEEK AS
ADDITIONAL NORTHERN STREAM ENERGY DIGS SOUTHEASTWARD THROUGH THE
LARGER SCALE TROUGH. THIS APPEARS TO BE SETTING UP SOME RAINFALL
FOR PORTIONS OF THE AREA ON MONDAY. HOWEVER...THE HEAVIEST RAINFALL
NOW APPEARS THAT IT WILL FALL FARTHER SOUTH ACROSS CENTRAL AND
SOUTHERN INDIANA MONDAY NIGHT INTO TUESDAY AS THE MAIN SOUTHERN
STREAM ENERGY EJECTS EASTWARD ACROSS THE LOWER MISSISSIPPI VALLEY.

FOLLOWING THIS SYSTEM...THE LARGE SCALE TROUGH WILL SHIFT EASTWARD
AND SET UP A QUASI ZONAL FLOW PATTERN ACROSS THE CONUS FOR THE
MIDDLE PART OF NEXT WEEK. OVERALL THIS WILL LEAD TO A COOL BUT DRY
WEATHER PATTERN FOR A FEW DAYS NEXT WEEK. HOWEVER...IT APPEARS THAT
THE WEATHER PATTERN MAY BECOME ACTIVE AGAIN BY THE LATER PART OF
NEXT WEEK AS POSITIVE HEIGHT ANOMALIES BUILD ACROSS THE NORTHERN
PACIFIC AND DRIVE A STRONG TROUGH FROM ALASKA SOUTHEASTWARD ACROSS
WESTERN NORTH AMERICA. THIS FLOW PATTERN LOOKS TO SET UP POSITIVE
HEIGHT ANOMALIES ACROSS THE SOUTHEASTERN CONUS AND HENCE SOUTHWEST
FLOW ALOFT ACROSS THE CENTRAL PORTION OF THE COUNTY. THIS
ATMOSPHERIC FLOW PATTERN MAY RESULT IN A WARM AND WETTER WEATHER
PATTERN INTO NEXT WEEKEND.

KJB

&&

.AVIATION...

//ORD AND MDW CONCERNS...UPDATED 03Z...

* SOUTHWEST WINDS INCREASING WITH GUSTS NEAR 25 KTS SATURDAY.

RATZER

//DISCUSSION...UPDATED 00Z...

WARM FRONTAL TROUGH ALONG MISSISSIPPI RIVER WILL MOVE EAST ACROSS
THE TERMINALS WHILE BECOMING LESS WELL-DEFINED OVERNIGHT. EARLIER
SURFACE PRESSURE FALLS ACROSS CENTRAL/NORTHEAST ILLINOIS HAVE
WEAKENED...WHICH ALONG WITH NIGHTFALL AND RESULTING WEAKENING OF
MIXING IN LOW LEVELS HAS ALLOWED EARLIER GUSTS TO BECOME MUCH MORE
SPORADIC. SOUTH TO SOUTH-SOUTHEAST WINDS AROUND 10 KTS SHOULD
PREVAIL THIS EVENING...EVENTUALLY DECREASING AND BECOMING MORE
SOUTHWEST OVERNIGHT AS THE GRADIENT RELAXES. VFR CONDITIONS TO
CONTINUE WITH LITTLE IN THE WAY OF CLOUD COVER EXPECTED THROUGH
THE NIGHT.

SOUTH-SOUTHWEST WINDS WILL INCREASE DURING THE DAY SATURDAY AS
DEEP LOW PRESSURE DEVELOPS OVER THE NORTHERN PLAINS. WINDS WILL
LIKELY GUST TO 25 KTS OR SO BY EARLY AFTERNOON...THOUGH MIXING
MAY BE LIMITED SOMEWHAT BY THICKENING HIGH LEVEL CLOUD DECK.
PRESSURE GRADIENT REMAINS TIGHT SATURDAY NIGHT WITH GUIDANCE
INDICATING SUSTATINED WINDS OF 15 KTS OR MORE OVERNIGHT. QUESTION
WILL BE HOW QUICKLY GUSTS DIMINISH TOWARD SUNSET BENEATH SHALLOW
INVERSION LAYER. FORECAST SOUNDINGS INDICATE WINDS APPROXIMATELY
21050KT AT AROUND 1500 FEET AGL BY MID SATURDAY EVENING...THUS
LLWS MAY BE A CONCERN SATURDAY NIGHT IF SURFACE WINDS DECOUPLE
MORE THAN EXPECTED. OTHERWISE...VFR MID-LEVEL CIGS CONTINUE TO
GRADUALLY LOWER/THICKEN BUT REMAIN ABOVE FL150 THROUGH THIS TAF
PERIOD.

RATZER

//ORD AND MDW CONFIDENCE...UPDATED 03Z...

* HIGH CONFIDENCE ALL ELEMENTS...EXCEPT MEDIUM HIGH CONFIDENCE IN
GUST TRENDS BY SATURDAY EVENING.

RATZER

//OUTLOOK FOR ORD/MDW FOR 12Z SUNDAY-12Z FRIDAY...UPDATED 00Z...

SUNDAY...CHANCE SHRA AND MVFR CIGS EARLY. WINDY. SWLY GUSTS TO 35
KT IN THE AFTERNOON.

MONDAY...CHANCE SHRA. MVFR CIGS POSSIBLE.

TUESDAY THROUGH THURSDAY...VFR.

RATZER

&&

.MARINE...
357 PM CST

WIND GUSTS HAVE BEEN SLOW TO DEVELOP TODAY DUE TO LINGERING CLOUD
COVER THAT IS INHIBITING MIXING. WITH THE COMBINATION OF LITTLE
CLOUD COVER AND COLD AIR ABOVE THE WARM LAKE...STILL EXPECTING GUSTS
TO 30 KT OVER THE SOUTHERN HALF OF THE LAKE AND GALES UP TO 35 KT
OVER THE NORTHERN HALF OF THE LAKE. SOUTHWEST FLOW CONTINUES
TOMORROW WITH GUSTS UP TO 25 KT AND INCREASING CLOUDS THROUGH THE
DAY. A DEEPENING LOW PASSES NORTH OF THE GREAT LAKES ON SUNDAY
BRINGING STRONG PRESSURE RISES BEHIND THE LOW AND CAA BEHIND THE
FRONT...GALES UP TO 45 KT ARE EXPECTED ESPECIALLY OVER THE NORTHERN
HALF OF THE LAKE. MODELS HAVE INDICATED DEEP MIXING WITH GUSTS
RANGING BETWEEN 45 AND 64 KT ACROSS THE NORTHERN HALF OF THE LAKE.
DECIDED TO STAY BELOW STORM FORCE WIND SPEEDS FOR NOW DUE TO THE
UNCERTAINTY BETWEEN THE MODELS. THAT BEING SAID...IF MODELS
CONTINUE TO SHOW POSSIBILITIES OF STORM FORCE WINDS...THE GALE WATCH
MAY BE UPGRADED TO A STORM WATCH OR WARNING.

AFTER THE SUNDAY HIGH END GALES...WINDS WILL STAY ELEVATED OUT OF
THE SOUTHWEST MONDAY INTO EARLY TUESDAY...WITH MAXIMUM WINDS IN THE
20 TO 30 KT RANGE. THEN YET ANOTHER DEEP LOW WILL MOVE NORTH OF
THE LAKE ON TUESDAY...TIGHTENING THE PRESSURE GRADIENT AND STEADILY
RAMPING WEST-SOUTHWEST WINDS UP THROUGH THE AFTERNOON. LOW END GALES
ARE POSSIBLE BY THE LATE AFTERNOON...ESPECIALLY FOR THE SOUTH HALF.
AFTER COLD FRONT PASSAGE TUESDAY EVENING...WINDS WILL TURN
WEST-NORTHWEST AND COLD AIR PUSHING ACROSS THE LAKE WILL MAKE FOR AN
UNSTABLE SET-UP AND PROLONG POSSIBLE GALES ACROSS THE ENTIRE
LAKE THROUGH TUESDAY NIGHT. HIGH PRESSURE WILL APPROACH FROM THE MID
MISSISSIPPI VALLEY LATE TUESDAY NIGHT...CAUSING WINDS TO DIMINISH
SOMEWHAT FOR THE SOUTH HALF OF THE LAKE ON WEDNESDAY...BUT THE
NORTH HALF WILL MAINTAIN A STRONGER PRESSURE GRADIENT AND BE SLOWER
TO COME DOWN.

JEE/RC

&&

.LOT WATCHES/WARNINGS/ADVISORIES...
IL...NONE.
IN...NONE.
LM...GALE WARNING...LMZ261-LMZ362-LMZ364-LMZ366-LMZ563-LMZ565-LMZ567-
LMZ868 UNTIL 2 AM SATURDAY.

GALE WATCH...LMZ080-LMZ261-LMZ362-LMZ364-LMZ366-LMZ563-LMZ565-
LMZ567-LMZ669-LMZ671-LMZ673-LMZ675-LMZ777-LMZ779-LMZ868-
LMZ870-LMZ872-LMZ874-LMZ876-LMZ878...6 AM SUNDAY TO
MIDNIGHT MONDAY.

SMALL CRAFT ADVISORY...NEARSHORE WATERS
UNTIL 3 AM SATURDAY.

GALE WATCH...LMZ740-LMZ741-LMZ742-LMZ743-LMZ744-LMZ745...9 AM
SUNDAY TO 9 PM SUNDAY.

&&

$$