806
FXUS63 KLOT 160531
AFDLOT
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE CHICAGO/ROMEOVILLE, IL
1231 AM CDT TUE SEP 16 2025
KEY MESSAGES
- WARM AND DRY CONDITIONS PERSIST THROUGH THE WORK WEEK.
- PERIODIC SHOWER AND THUNDERSTORM CHANCES RETURN FOR THE WEEKEND
(20-40%).
DISCUSSION
ISSUED AT 136 PM CDT MON SEP 15 2025
A BLOCKY UPPER-LEVEL FLOW PATTERN, CENTERED ACROSS THE GREAT
LAKES, WILL CONTINUE TO SUPPORT QUIESCENT WEATHER CONDITIONS
ACROSS OUR AREA THROUGH THE WEEK. ACCORDINGLY, DRY WEATHER WITH
MOSTLY CLEAR SKIES EACH DAY WILL FOSTER UNSEASONABLY WARM
TEMPERATURES, WITH INLAND HIGHS IN THE 80S TO NEAR 90 (WARMEST
TOWARD WESTERN AND CENTRAL ILLINOIS) THROUGH THE REMAINDER OF THE
WORK WEEK. CLOSER TO THE LAKE, RELATIVELY WEAK SURFACE FLOW AMIDST
EXPANSIVE SURFACE HIGH PRESSURE WILL FAVOR DAILY INLAND DRIFTING
LAKE BREEZES. THIS WILL THUS RESULT IN COOLER TEMPERATURES (MAINLY
IN THE 70S) NEAR THE LAKE MICHIGAN LAKESHORE.
WHILE QUIET AND DRY WEATHER WILL PERSIST IN THIS BLOCKED PATTERN
THROUGH THE REST OF THE WORK WEEK, THIS PATTERN WILL BEGIN TO
BREAK LATE IN THE WEEK AS A WESTERN TROUGH (AND/OR POTENTIAL CUT-
OFF LOW) BEGINS TO SLIDE EASTWARD TOWARDS THE GREAT LAKES. THE NET
RESULT OF THIS WILL BE INCREASING CHANCES FOR PERIODIC SHOWERS
AND THUNDERSTORMS FOR THIS WEEKEND INTO EARLY NEXT WEEK. THIS
WILL ALSO BE PAIRED WITH COOLER MORE SEASONABLE TEMPERATURES IN
THE 70S.
KJB
AVIATION /06Z TAFS THROUGH 12Z WEDNESDAY/
ISSUED AT 1231 AM CDT TUE SEP 16 2025
NO MAJOR FORECAST CONCERNS ARE EXPECTED THROUGH THE TAF PERIOD
AS HIGH PRESSURE REMAINS OVERHEAD. THEREFORE, EXPECT LIGHT AND
VARIABLE WINDS TONIGHT TO BECOME EAST-NORTHEAST TUESDAY MORNING
WITH SPEEDS IN THE 5-7 KT RANGE. SKIES WILL REMAIN MOSTLY CLEAR
THROUGH THE PERIOD THOUGH SOME OCCASIONAL PASSING CIRRUS IS
POSSIBLE ESPECIALLY AT RFD.
FINALLY, THERE IS SOME SHALLOW FOG DEVELOPING IN FAR NORTHEAST
IL AND SOUTHERN WI. GIVEN THE LARGE TEMPERATURE-DEW POINT
DEPRESSIONS (AROUND 5-6 DEGREES) SUSPECT FOG WILL STRUGGLE TO
DEVELOP AT THE TERMINALS AND THUS HAVE FORGONE A FORMAL MENTION.
THAT SAID, DID ADD A TEMPO AT GYY FOR SOME 5SM BR GIVEN THE LOW
TEMP-DEW POINT DEPRESSION HERE AND SOME FOG BEING NOTED IN LAKE
COUNTY, IN. FOG WILL ERODE AFTER DAYBREAK TUESDAY MORNING.
YACK
LOT WATCHES/WARNINGS/ADVISORIES
IL...NONE.
IN...NONE.
LM...NONE.
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