337 AM CDT
MAIN CONCERNS FOR THE MORNING UPDATE CONTINUE TO BE THE DEVELOPING
HIGH WIND AND HEAVY RAIN EVENT SETTING UP FOR THE NEXT 36 HOURS.
LITTLE CHANGE TO THE GOING FORECAST HAS BEEN NECESSARY AS THE MODELS
HAVE BEEN DEMONSTRATING VERY GOOD CONTINUITY WITH EACH
OTHER...RUN-TO-RUN...AND WITH THE DEVELOPING PATTERN. THE MAIN
ISSUE FOR TONIGHT HAS BEEN TO DECIDE ON WHAT TO DO WITH HEADLINES.
IN A NUTSHELL...HAVE UPGRADED THE HIGH WIND WATCH TO A HIGH WIND
WARNING FOR THE COUNTIES ADJACENT TO LAKE MICHIGAN...WHILE ADDING A
WIND ADVISORY TO THE ADJACENT WESTERN AND SOUTHERN COUNTIES...BUT
NOT AS FAR WEST AS THE I-39 CORRIDOR.
FOR THE REMAINDER OF THE NIGHT AND INTO THE MORNING HOURS...ONE SFC
LOW CONTINUES TO TRACK NWD INTO THE UPPER OHIO VALLEY AS THE
SUB-TROPICAL LOW MOVES ONSHORE FROM THE NERN GLFMEX TO SRN GEORGIA.
THE GUIDANCE REMAINS CONSISTENT ON SLOWLY TRACKING THE MORE NORTHERN
SFC LOW SLOWLY THROUGH OHIO TODAY AND THEN WRAPPING MORE NWWD BACK
INTO NRN INDIANA BY EARLY THURSDAY MORNING. AS THIS OCCURS...THE
SUB-TROPICAL SFC LOW WILL BE ABSORBED INTO THE OTHER LOW...AIDING IN
FURTHER DEEPENING OF A CONSOLIDATED LOW OF 988MB OVER NRN INDIANA.
THE PRESSURE GRADIENT OVER THE AREA IS ALREADY STRENGTHENING RAPIDLY
WITH WINDS IN EXCESS OF 30KT ALREADY OBSERVED OVER SRN LAKE MICHIGAN
AND THE COASTAL AREAS OF NERN IL/NWRN IN. EXPECT THAT WINDS WILL
CONTINUE TO INCREASE THROUGH THE MORNING. THE LATEST MODEL RUNS ARE
IN GOOD AGREEMENT ON ADVERTISING 925MB WINDS OF 50-60KT BY EARLY
THIS AFTERNOON. WITH FAIRLY STEEP LOW LEVEL LAPSE RATES DEVELOPING
TODAY...SEE LITTLE REASON WHY THE STRONG WINDS WILL NOT MIX DOWN TO
THE SURFACE...ESPECIALLY INVOF HEAVIER RAIN SHOWERS. SO...HAVE
UPGRADED THE HIGH WIND WATCH TO A HIGH WIND WARNING. EXPECT THAT
THE STRONGEST WINDS WILL BE LONG THE SHORE OF LAKE MICHIGAN...WITH
WIND SPEEDS DROPPING OFF FARTHER INLAND. WILL ALSO ISSUE A WIND
ADVISORY FOR LOCATIONS OUT TO THE FOX VALLEY AND THE I-55 CORRIDOR.
STRONG WINDS WILL CONTINUE THROUGH TONIGHT. THE LOW WILL FINALLY
LIFT OUT TO THE NORTHEAST THURSDAY MORNING. BRISK NORTH TO
NORTHWEST WINDS WILL CONTINUE ACROSS THE AREA THROUGH THE DAY
THURSDAY...BUT SHOULD DECREASE BELOW HEADLINE CRITERIA BY LATE
MORNING. ONE SIGNIFICANT IMPACT OF THE STRONG NORTH WINDS WILL BE
ON THE LAKEFRONT LOCATIONS WHERE STRONG WINDS WILL DRIVE WAVES AS
HIGH AS 20 TO 25 FEET. THIS WILL LEAD TO COASTAL FLOODING...BEACH
EROSION...ESPECIALLY FOR THE NWRN INDIANA LOCATIONS...AND WATER
SPLASHING UP TO ROADWAYS ADJACENT TO THE LAKE...INCLUDING LAKESHORE
DRIVE IN DOWNTOWN CHICAGO.
IN ADDITION TO THE STRONG WINDS...HEAVY RAIN WILL BE A CONCERN.
WITH THE SYSTEM POSSIBLY ABLE TO TAP SOME SUB-TROPICAL
MOISTURE...HAVE INCREASED QPF AMOUNTS OVER THE AREA. WITH PWATS
APPROACHING 1 INCH WRAPPING AROUND THE LOW...EXPECT PERIODS OF HEAVY
RAIN...ESPECIALLY FOR THE ERN PORTIONS OF THE CWA. NOW EXPECTING
PCPN AMOUNTS OF 2 TO 2.5 INCHES OVER NWRN INDIANA...DECREASING TO
0.5 TO 0.75 INCHES ALONG THE I-39 CORRIDOR. GIVEN THAT THE AREA HAS
NOT SEEN A SIGNIFICANT AMOUNT OF PCPN OVER RECENT WEEKS...AREA
RIVERS SHOULD HAVE ADEQUATE CAPACITY TO HANDLE THE RUNOFF.
HOWEVER...WITH THE HEAVIEST RAIN EXPECTED TO FALL OVER NWRN
INDIANA...THE KANKAKEE RIVER WILL NEED TO BE MONITORED FOR POSSIBLE
FLOODING PROBLEMS. ALSO...IF THERE IS ANY CONVECTIVE ENHANCEMENT TO
RAINFALL RATES...LOCATIONS EAST OF THE I-55 CORRIDOR WILL NEED TO BE
MONITORED FOR URBAN AND SMALL STREAM FLOODING PROBLEMS.
AS THE LOW LIFTS OUT ON THURSDAY AND HIGH PRESSURE BUILDS IN FROM
THE NRN PLAINS...COOLER AIR WILL FILTER OVER THE AREA...WITH
TEMPERATURES REMAINING WELL BELOW NORMAL INTO FRIDAY. HIGHS FOR
THURSDAY SHOULD ONLY BE IN THE UPPER 40S TO AROUND 50...WHILE
OVERNIGHT LOWS SHOULD DROP INTO THE LOWER TO MIDDLE 30S BY FRIDAY
MORNING. SOME MODERATION IS EXPECTED FOR THE WEEKEND AS MORE ZONAL
FLOW AND WEAK RIDING SETS UP OVER THE CNTRL CONUS. NO ADDITIONAL
PCPN IS EXPECTED FOR FRIDAY THROUGH SATURDAY NIGHT...WHILE HIGH
TEMPERATURES CLIMB BACK INTO THE UPPER 50S TO AROUND 60.
KREIN
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 08Z...
* STRONG WINDS APPROACHING AND POSSIBLY SURPASSING 40 KTS.
* CONDITIONS DROPPING TO IFR AND POSSIBILITY LIFR. BMD
//DISCUSSION...UPDATED 06Z...
A STRONG FALL STORM WILL IMPACT THE CHICAGO AND ROCKFORD TERMINALS
THROUGH THE DAY AND INTO THE NIGHT WEDNESDAY...WITH STRONG WINDS
AND IFR/LIFR CONDITIONS EXPECTED ALONG WITH PERIODS OF MODERATE TO
HEAVY RAIN. AN ELONGATED AREA OF LOW PRESSURE OVER THE
SOUTHEASTERN UNITED STATES WILL CONTINUE TO DEVELOP THROUGH THE
DAY. STRONG PRESSURE FALLS OVER THE UPPER OHIO VALLEY WILL
INTENSIFY THROUGH THE MORNING AND AFTERNOON AS SURFACE
CYCLOGENESIS OCCURS IN RESPONSE TO VIGOROUS UPPER LEVEL SYSTEM.
STRONG PRESSURE FALLS IN ADDITION TO A TIGHTENING PRESSURE
GRADIENT WILL CAUSE WINDS TO INTENSIFY ACROSS THE UPPER
MIDWEST...WITH 50 KT+ WINDS EXPECTED OVER LAKE MICHIGAN POSSIBLY
IMPACTING AREAS RIGHT ALONG THE LAKESHORE SUCH AS GYY. WINDS WILL
DROP OFF AWAY FROM THE LAKE...BUT STILL EXPECT GUSTS TO INCREASE
WELL INTO THE 30KT RANGE BY LATE MORNING. NNE WINDS WILL BACK TO
THE NNW BY THIS EVENING AS THE LOW GRADUALLY LIFTS NORTH THROUGH
THE DAY.
IN ADDITION TO THE WINDS...EXPECT CIG/VIS CONDITIONS TO DETERIORATE
THROUGH THE DAY AS WELL. FOR THE REMAINDER OF TONIGHT...SOME SHOWERS
ARE GENERATING OFF OF LAKE MICHIGAN...AND AREA OCCASIONALLY
DROPPING CIGS TO HIGH END MVFR...BUT OTHERWISE EXPECT PREVAILING VFR
CONDITIONS THROUGH EARLY THIS MORNING. THAT SAID...A DOWNWARD TREND
IS EXPECTED AS 500MB HEIGHT FALLS OVERSPREAD THE AREA AND THE COLUMN
SATURATES. EXACT TIMING IS A LITTLE UNCERTAIN...BUT EXPECT SHOWERY
PRECIP THIS MORNING TO EVENTUALLY GIVE WAY TO MORE WIDESPREAD AND
STEADY RAINFALL THIS AFTERNOON AS DEFORMATION ZONE MOVES OVERHEAD
FROM THE SOUTHEAST. CONDITIONS ARE EXPECTED TO BOTTOM OUT LATE
TONIGHT AS THE LOW CENTER RETROGRADES SOMEWHAT INTO NORTHERN
INDIANA. A MIX OF GUIDANCE SUGGESTS THAT CONDITIONS SHOULD DROP TO
AT LEAST IFR...BUT LIFR CONDS NOT OUT OF THE REALM OF POSSIBILITY.
IMPROVEMENT IS EXPECTED BEYOND THE CURRENT TAF PERIOD...LATE
THURSDAY MORNING OR THURSDAY AFTERNOON. BMD
//ORD AND MDW CONFIDENCE...UPDATED 08Z...
* MEDIUM CONFIDENCE IN WIND SPEED...HIGH CONFIDENCE IN DIRECTION.
* MEDIUM CONFIDENCE IN CIGS DROPPING TO IFR...LOW CONFIDENCE IN
TIMING. BMD
//OUTLOOK FOR ORD/MDW FOR 12Z THURSDAY-12Z TUESDAY...UPDATED 00Z...
THURSDAY...CHANCE OF SHOWERS...IFR POSSIBLE
FRIDAY THROUGH MONDAY...VFR
SHEA
&&
.MARINE...
300 AM CDT
STORM FORCE WINDS NOW EXPECTED ACROSS ALL OF LAKE MICHIGAN BY
LATE AFTERNOON/EARLY THIS EVENING.
ONLY SIGNIFICANT CHANGE THIS MORNING IS TO UPGRADE THE NORTHERN
THIRD OR SO OF LAKE MICHIGAN FROM A GALE WARNING TO A STORM WARNING.
AN ELONGATED AREA OF LOW PRESSURE EXTENDS FROM SOUTHERN GEORGIA
NORTH INTO SOUTHERN OHIO. THIS LOW WILL CONSOLIDATE DURING THE DAY
AS IT DEEPENS...REACHING NORTHWEST OHIO/FAR NORTHEAST INDIANA LATE
THIS EVENING. A LARGE RIDGE OF HIGH PRESSURE EXTENDING FROM HUDSON
BAY TO TEXAS WILL SLOWLY MOVE EAST TODAY AND TONIGHT. THE GRADIENT
WILL TIGHTEN RAPIDLY BETWEEN THESE TWO FEATURES THIS AFTERNOON INTO
THIS EVENING. SO EXPECTING A PERIOD OF STEADILY INCREASING GALES
FROM NOW THROUGH EARLY AFTERNOON...FROM SOUTH TO NORTH ACROSS THE
LAKE. THEN STORM FORCE WINDS DEVELOPING BY LATE AFTERNOON ACROSS
THE SOUTH...AND SPREADING NORTH THROUGH THE EVENING. WHILE THE LOW
WILL BEGIN TO WEAKEN AS IT LIFTS NORTHEAST ACROSS THE EASTERN GREAT
LAKES THURSDAY...AND THUS EXPECT STORM FORCE WINDS TO END BY EARLY
THURSDAY AFTERNOON...THE GRADIENT WILL STILL REMAIN QUITE STRONG
AND EXPECT GALES TO PERSIST WELL INTO THURSDAY EVENING BEFORE
FINALLY DIMINISHING TO 30 KTS OR LESS LATE THURSDAY NIGHT. A RIDGE
OF HIGH PRESSURE WILL MOVE ACROSS THE LAKE FRIDAY...WITH A WEAK
TROUGH/COLD FRONT MOVING ACROSS THE WESTERN LAKES SATURDAY. CMS
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...HIGH WIND WARNING...ILZ006-ILZ014...3 PM WEDNESDAY TO 10 AM
THURSDAY.
LAKESHORE FLOOD WARNING...ILZ006-ILZ014...3 PM WEDNESDAY TO 4 PM
THURSDAY.
WIND ADVISORY...ILZ005-ILZ012-ILZ013-ILZ020-ILZ021-ILZ022-ILZ023-
ILZ032-ILZ033-ILZ039...3 PM WEDNESDAY TO 10 AM THURSDAY.
IN...HIGH WIND WARNING...INZ001-INZ002...3 PM WEDNESDAY TO 10 AM
THURSDAY.
LAKESHORE FLOOD WARNING...INZ001-INZ002...3 PM WEDNESDAY TO 9 PM
THURSDAY.
WIND ADVISORY...INZ010-INZ011-INZ019...3 PM WEDNESDAY TO 10 AM
THURSDAY.
LM...GALE WARNING...LMZ080-LMZ567-LMZ669-LMZ671-LMZ673-LMZ675-LMZ740-
LMZ741-LMZ742-LMZ743-LMZ744-LMZ745-LMZ777-LMZ779-LMZ868-
LMZ870-LMZ872-LMZ874-LMZ876-LMZ878 UNTIL 3 PM WEDNESDAY.
STORM 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...3 PM WEDNESDAY TO 3 PM THURSDAY.
GALE WARNING...LMZ261-LMZ362-LMZ364-LMZ366-LMZ563-LMZ565...10 AM
WEDNESDAY TO 3 PM WEDNESDAY.
&&
$$
