Wednesday, October 5, 2011

Area Forecast Discussion 09:06:28.3246011

.DISCUSSION...
333 AM CDT

BENIGN WEATHER WILL CONTINUE THROUGH THE END OF THE WEEK...THROUGH
THE WEEKEND...AND MOST LIKELY INTO EARLY NEXT WEEK. TODAY AND
TOMORROW WILL BE NEARLY CARBON COPIES OF THE PREVIOUS DAYS...HOWEVER
SLIGHTLY WARMER GIVEN ATMOSPHERIC PARCELS REMAIN PARCHED. THIS BOOK
CONTINUES TO READ THE SAME...WITH A DRY ENDING.

BROAD ANTI-CYCLONIC FLOW REMAINS CENTERED OVER THE OHIO RIVER
VALLEY...PROVIDING A MAJOR INFLUENCE ON THE SENSIBLE WEATHER ACROSS
THE GREAT LAKES REGION. IR IMAGERY EARLY THIS MORNING CONTINUES TO
DEPICT SOME CIRRUS CLOUDS ACROSS PORTIONS OF
MICHIGAN/INDIANA...STRETCHING NORTHWEST THROUGH THE ARROWHEAD OF
MINNESOTA. VWP FROM KLOT OVERNIGHT HAS CONTINUED TO SHOW WINDS JUST
OFF OF THE DECK ARND 10KT...WHICH COULD BE ONE OF THE LIMITING
FACTORS AS TO WHY TEMPERATURES IN MANY LOCATIONS ARE NOT RADIATING
EFFICIENTLY AS IN PREVIOUS NIGHTS. SOME PATCHY FOG HAS ONCE AGAIN
DEVELOPED EARLY THIS MORNING...HOWEVER EXPECT THIS TO REMAIN PATCHY
AND LIFT SHORTLY AFTER SUNRISE. WITH SUCH A REDUCED HEAT
CAPACITY...AND DRY WEATHER FROM THE PAST SEVERAL DAYS...A LARGE
DIURNAL SWING IN TEMPERATURES IS EXPECTED TODAY. TEMPERATURES WILL
PRIMARILY BE IN THE MID/UPR 70S...WITH ARND 80 DEGREES FOR MANY
LOCATIONS ALONG AND SOUTH OF I-80. SOUTHERLY WINDS WILL REMAIN
LIGHT...HOWEVER THIS SHOULD BE ENOUGH TO DISPLACE ANY LAKE BREEZE
FROM PROGRESSING TOO FAR INLAND. THE LARGEST PUSH INLAND MAY OCCUR
OVER LAKE COUNTY. ALONG THE IMMEDIATE SHORELINE TEMPS WILL HOVER IN
THE MID 70S FOR MOST OF THE DAY. THURSDAY WILL BE NEARLY A CARBON
COPY AS MINIMAL SOLAR SHIELDING IS ANTICIPATED AND CONTINUED
INFLUENCE FROM THE ANTI-CYCLONIC FLOW.

THE OTHER CONCERN IS FOR MIN RH VALUES APPROACHING 30 PERCENT THIS
AFTERNOON. ALTHOUGH WINDS WILL REMAIN FAIRLY LIGHT...IF WINDS ARE
ABLE TO KICK UP ABOVE 10KT...THIS MAY PRODUCE ADDTL MIXING AND
REDUCED RH VALUES THIS AFTN. AT THIS TIME NOT ANTICIPATING
HEADLINES...HOWEVER WILL NEED TO CLOSELY MONITOR.

FRIDAY THROUGH TUESDAY...
HIGH CONFIDENCE REMAINS IN THE EXTENDED...WITH RESPECT TO A
CONTINUED BLOCKY PATTERN. ANOMALOUS TROUGH ACROSS THE SOUTHWEST
UNITED STATES WILL STEADILY PUSH EAST...HOWEVER IT WILL STRUGGLE TO
EFFICIENTLY EJECT THE DOWNSTREAM RIDGE THAT WILL AMPLIFY DUE TO THE
STRENGTH OF THE TROUGH. THIS WILL MOST LIKELY RESULT IN A WEAKENING
TROUGH ACROSS THE SOUTHERN ROCKIES...AS THE BLOCKING 500MB RIDGE
LIFTS NORTH INTO THE OHIO VALLEY STRETCHING NORTH THROUGH QUEBEC AND
THE CANADIAN MARITIME BY LATE IN THE WEEKEND. WHILE OPERATIONAL
SOLUTIONS CONTINUE TO ADVERTISE SOME PRECIP FORMING ALONG A
QUASI-STATIONARY NORTH-SOUTH ORIENTED BOUNDARY FOR THE CENTRAL
PLAINS/UPPER MIDWEST LATE IN THE WEEKEND/EARLY NEXT WEEK...ENSEMBLES
CONTINUE TO SUGGEST THE HIGHEST PROBABILITY OUTCOME WILL BE DRY
WEATHER. THUS HAVE HEDGED THE FORECAST TOWARDS THIS AND MAINTAINED A
DRY FORECAST THROUGH THE EXTENDED PERIODS. GUIDANCE HAS ALSO TRENDED
TOWARDS CLIMO FOR THE TEMPERATURES...HOWEVER GIVEN SUCH A DRY
STRETCH OF WEATHER WITH REDUCED HEAT CAPACITY...THIS SHOULD ALLOW
FOR EFFICIENT WARMING OF PARCELS AT THE SFC. THUS HAVE YET AGAIN
HEDGED THE FORECAST WARMER THAN GUIDANCE IN THE EXTENDED.

BEACHLER

&&

.FIRE WEATHER...
333 AM CDT

DRY WEATHER WILL CONTINUE WITH DEW POINTS EXPECTED TO REMAIN IN
THE 40S...POSSIBLY REACHING 50 DEGREES FOR FAR NORTHERN SECTIONS
OF ILLINOIS. WINDS WILL CONTINUE TO REMAIN LIGHT FROM THE
SOUTH...OR AROUND 5 TO 10 MPH FOR MOST LOCATIONS. THIS COUPLED
WITH AFTERNOON TEMPERATURES WARMING WELL INTO THE 70S...AND ARND
80 DEGREES WILL RESULT IN RELATIVE HUMIDITY VALUES IN THE LOW/MID
30 PERCENT RANGE. THE AREA OF GREATEST CONCERN WILL BE ALONG AND
SOUTH OF A DIXON TO KANKAKEE LINE.

BEACHLER

&&

.AVIATION...

//ORD AND MDW CONCERNS...UPDATED 14Z...

* LIGHT WINDS FAVORING SOUTHWEST THIS MORNING...SHIFTING TO EAST
TO SOUTHEAST LATE AFTERNOON.

PAW

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

IT WILL BE ANOTHER QUIET WEATHER DAY WITH NO MAJOR WEATHER CONCERNS
EXPECTED. WINDS WILL START OFF CALM THIS MORNING. HOWEVER...SOUTH
TO SOUTHWESTERLY FLOW WILL COMMENCE LATER THIS MORNING AS THE
SURFACE HIGH CONTINUES TO PUSH EAST ACROSS THE OHIO VALLEY.
THEN...DURING THE AFTERNOON THE FLOW LOOKS TO BACK TO THE EAST OFF
THE LAKE AS THE SYNOPTIC SCALE FLOW SHIFTS SOUTHEASTWARD ALONG THE
BACK SIDE OF THE SURFACE RIDGE OF HIGH PRESSURE. HOWEVER...IN
SPITE OF THIS WIND SHIFT...THE SPEEDS WILL REMAIN AT OR UNDER 10
KT.

KJB

//ORD AND MDW CONFIDENCE...UPDATED 14Z...

* HIGH CONFIDENCE IN ALL FORECAST ELEMENTS.

PAW

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

THURSDAY NIGHT THROUGH TUESDAY...VFR.

KJB

&&

.MARINE...
242 AM CDT

LIGHT S TO SW WINDS WILL GRADUALLY BECOME SE AND INCREASE TODAY
AND TONIGHT WITH A LARGE RIDGE OF HIGH PRESSURE EXTENDING FROM
HUDSON BAY S TO THE GULF OF MEXICO CONTINUE TO SLOWLY DRIFT E.
S WINDS WILL CONTINUE TO INCREASE FRI AND FRI NIGHT AS A TROUGH
OF LOW PRESSURE OVER THE HIGH PLAINS FORMS A DEEPENING LOW AS IT
LIFTS NE FROM THE DAKOTAS TO NORTHERN MANITOBA. S TO SW WINDS WILL
SLOWLY DIMINISH SAT NIGHT AS THE LOW MOVES FURTHER NE TO OVER
HUDSON BAY.

TRS

&&

.LOT WATCHES/WARNINGS/ADVISORIES...
IL...NONE.
IN...NONE.
LM...NONE.
&&

$$