357
FXUS63 KLOT 100530
AFDLOT
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE CHICAGO/ROMEOVILLE, IL
1230 AM CDT WED SEP 10 2025
KEY MESSAGES
- MOSTLY DRY WEATHER EXPECTED THE REMAINDER OF THE WORK WEEK
WITH A CONTINUED GRADUAL WARMING TREND.
- UNSEASONABLY WARM WITH A (LESS THAN 30 PERCENT) CHANCE OF
SCATTERED SHOWERS AND SOME THUNDERSTORMS THIS WEEKEND.
DISCUSSION
ISSUED AT 226 PM CDT TUE SEP 9 2025
A BROAD TROUGH IS EVIDENT ON WATER VAPOR IMAGERY EARLY THIS
AFTERNOON DIGGING SOUTHEASTWARD INTO THE MIDWEST. SEVERAL,
SMALLER VORTS ARE EMBEDDED WITHIN THIS BROADER TROUGH WITH THE
MOST PROMINENT ONE OVER SOUTHWEST MN/NORTHWEST IA. THE LARGER,
PARENT TROUGH, WITH EMBEDDED VORTS, WILL MOVE ACROSS OUR AREA
LATER TONIGHT AND WEDNESDAY.
AIR MASS OVER OUR AREA IS QUITE DRY WITH PRECIPITABLE WATER OF
ONLY 0.44" ON THE KILX 12Z SOUNDING, WHICH IS RIGHT AROUND THE
DAILY RECORD MIN. THERE IS AN AXIS WITH HIGHER MOISTURE FROM THE
WESTERN CORN BELT NORTHEAST INTO THE UPPER GREAT LAKES, BUT WITH
LOW LEVEL FLOW LARGELY REMAINING SOUTH OR EVEN SOUTHEASTERLY,
THIS AXIS OF GREATER MOISTURE WILL STRUGGLE TO MOVE EASTWARD. AS
THE UPPER TROUGH PROGRESSES EASTWARD, IT WILL ENCOUNTER AND
INCREASINGLY PARCHED AIR MASS. AN INCREASE/THICKENING OF MID-
HIGH LEVEL CLOUDINESS IS EXPECTED TONIGHT WITH CLOUDINESS
LINGERING INTO WEDNESDAY. STRONGER ASCENT, LIKELY FOCUSED NEAR
THE STRONGER SMALLER EMBEDDED VORTS, WILL LIKELY BE ENOUGH FOR
PLENTY OF VIRGA AND PERHAPS SOME SPRINKLES REACHING THE SURFACE
LATE TONIGHT AND POSSIBLY INTO WEDNESDAY. FOR NOW CONFINED THE
SPRINKLE CHANCES IN THE GRIDS TO OUR NORTHWESTERN CWA LATER
TONIGHT, BUT CERTAINLY WOULDN'T BE HARD TO ENVISION THOSE
SPRINKLE CHANCES NEEDING TO BE EXTENDED FARTHER EAST AND INTO
THE DAYTIME HOURS WEDNESDAY.
TEMP FORECAST IS A BIT TRICKY WITH LOW LEVEL THERMAL FIELDS
FAVORING TEMPS WARMING TOWARD IF NOT INTO THE LOWER 80S, THOUGH
EXTENT AND THICKNESS OF CLOUDINESS COULD RESULT IN TEMPS BEING
HELD A FEW DEGREES COOLER, ESPECIALLY NORTHERN/NORTHWESTERN CWA.
SUNSHINE RETURNS THURSDAY AND FRIDAY WHICH SHOULD ALLOW TEMPS TO
CLIMB INTO THE 80S BOTH DAYS, THOUGH WEAK LAKES BREEZES WILL
KEEP TEMPS A BIT COOLER (70S) NEAR THE LAKE BOTH AFTERNOONS.
A HIGHLY AMPLIFIED, BLOCKY, AND FAIRLY WONKY PATTERN IS EXPECTED
TO DEVELOP OVER NORTH AMERICAN THIS WEEKEND WITH HIGHLY
AMPLIFIED UPPER RIDGING OVER THE CENTRAL PART OF THE U.S. MEDIUM
RANGE GUIDANCE HAS THE UPPER RIDGE CENTER VERY NEAR OUR AREA,
WHICH FAVOR DRY, WARM CONDITIONS, HOWEVER, SHORTWAVE TROUGH
DIGGING SOUTH INTO THE EASTERN GREAT LAKES COULD ALLOW A WEAK
COLD FRONT TO MOVE ACROSS OUR AREA LATER IN THE WEEKEND. CAN'T
RULE OUT A SHOWER OR STORM AT SOME POINT THIS WEEKEND, BUT THE
VAST MAJORITY (ALL?) OF THE UPCOMING WEEKEND LOOKS DRY AND VERY
WARM.
- IZZI
AVIATION /06Z TAFS THROUGH 12Z THURSDAY/
ISSUED AT 1229 AM CDT WED SEP 10 2025
VFR CONDITIONS WILL PERSIST THROUGH THE PERIOD AS MID-LEVEL
CLOUDS AROUND OR ABOVE 10KFT FILTER OVER THE AREA IN RESPONSE TO
A SLOW- MOVING WAVE CROSSING THE SOUTH HALF OF WISCONSIN. SHRA
ASSOCIATED WITH THE WAVE ARE EXPECTED TO REMAIN NORTH OF THE
TERMINALS, THOUGH ISOLATED SPRINKLES CANNOT BE FULLY RULED OUT
(PARTICULARLY AT RFD) THROUGH THIS AFTERNOON AS MID-LEVEL VIRGA
EVAPORATES THROUGH A DRY SUB-CLOUD LAYER.
SSE WINDS UP TO AROUND 5 KNOTS EARLY THIS MORNING WILL
GRADUALLY SHIFT SSW THROUGH SUNRISE. A LAKE BREEZE IS THEN
EXPECTED TO SHIFT WINDS ENE UP TO 10 KNOTS AROUND 20Z AT MDW AND
21Z AT ORD. E OR ENE WINDS WILL THEN PREVAIL THROUGH TONIGHT.
KLUBER
LOT WATCHES/WARNINGS/ADVISORIES
IL...NONE.
IN...NONE.
LM...NONE.
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