227
FXUS63 KLOT 221906
AFDLOT
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE CHICAGO/ROMEOVILLE, IL
206 PM CDT FRI AUG 22 2025
KEY MESSAGES
- SLIGHT CHANCE (20%) FOR A FEW THUNDERSTORMS SATURDAY
AFTERNOON.
- FALL-LIKE TEMPERATURES EARLY/MID NEXT WEEK.
DISCUSSION
ISSUED AT 206 PM CDT FRI AUG 22 2025
A STRONG UPPER LOW AND AN ASSOCIATED SURFACE LOW OVER MANITOBA
WILL SHIFT EASTWARD INTO ONTARIO TONIGHT INTO SATURDAY. WHILE THIS
LOW WILL STAY WELL NORTH-NORTHEAST OF OUR AREA, AN ASSOCIATED
COLD FRONT SHIFTING SOUTHWARD ACROSS THE UPPER MIDWEST THIS
EVENING WILL SHIFT ACROSS OUR AREA DURING THE DAY ON SATURDAY. A
LOW POTENTIAL (~20%) FOR A PERIOD OF WIDELY SCATTERED SHOWERS (AND
MAYBE A THUNDERSTORM) WILL EXIST WITH THIS FRONTAL BOUNDARY
BEGINNING LATE TONIGHT (AFTER 2 AM) ACROSS FAR NORTHWESTERN IL,
THEN DURING THE EARLY TO MID MORNING HOURS OF SATURDAY ACROSS THE
MUCH OF NORTHERN IL NORTH OF I-80. MOST AREAS ARE LIKELY TO REMAIN
DRY, AND IN THE AREAS IT DOES RAIN AMOUNTS WILL REMAIN LIGHT
(UNDER A TENTH OF AN INCH). A FEW ADDITIONAL ISOLATED TO WIDELY
SCATTERED SHOWERS AND THUNDERSTORMS WILL BE POSSIBLE (~20% CHANCE)
WITH THE FRONTAL BOUNDARY SATURDAY AFTERNOON, PRIMARILY TO TO
SOUTHEAST OF I-55.
THE CANADIAN UPPER LOW WILL CARVE OUT DEEP MID-UPPER LEVEL TROUGH
ACROSS THE GREAT LAKES SUNDAY INTO THE FIRST HALF OF NEXT WEEK.
THIS WILL FAVOR A PERIOD OF BELOW AVERAGE AND RATHER PLEASANT
TEMPERATURES NEXT WEEK AS A MUCH COOLER AUTUMN-LIKE AIRMASS SHIFTS
INTO THE AREA ON BREEZY WEST-NORTHWESTERLY WINDS IN THE WAKE OF
SATURDAY'S COLD FRONT. HIGH TEMPERATURES IN THIS AIRMASS WILL BE
FAVORED TO ONLY BE IN THE LOW TO MID 70S SUNDAY THROUGH THE MIDDLE
OF NEXT WEEK. COOL OVERNIGHT LOWS ARE ALSO EXPECTED, WITH
READINGS LIKELY TO DROP INTO THE 40S TO LOWER 50S OUTSIDE OF
CHICAGO! LATE IN THE WEEK, TEMPERATURES SHOULD BEGIN TO SLOWLY
MODERATE BACK CLOSE TO THE 80 DEGREE MARK.
OUTSIDE OF SOME POSSIBLE LAKE EFFECT SHOWERS EARLY NEXT WEEK
ACROSS PARTS OF NORTHWESTERN IN, AN EXTENDED PERIOD OF QUIET AND
DRY WEATHER IS EXPECTED NEXT WEEK.
KJB
AVIATION /18Z TAFS THROUGH 00Z SUNDAY/
ISSUED AT 1234 PM CDT FRI AUG 22 2025
PERIODS OF LOW-END CUMULUS WILL PERSIST THROUGH MUCH OF THE
PERIOD, WITH BKN COVERAGE THIS AFTERNOON AND AGAIN LATE TONIGHT
INTO SATURDAY MORNING. ISOLATED VFR SHRA ARE POSSIBLE (10-20
PERCENT CHANCE) WITH A COLD FRONT CROSSING THE AREA FROM THE
PRE-DAWN HOURS THROUGH MID-MORNING SATURDAY, BUT POTENTIAL AND
COVERAGE REMAINS TOO LOW TO INCLUDE IN THE TAF AT THIS TIME.
A WEAK LAKE MODIFIED BOUNDARY CURRENTLY DEVELOPING OVER MDW AND
EAST OF ORD SHOULD BEGIN TO DRIFT FARTHER INLAND/WEST THIS
AFTERNOON. CURRENT LIGHT WINDS GENERALLY WITHIN THE NW QUADRANT
AT ORD WILL SHIFT SE UNDER 10 KNOTS MID/LATE AFTERNOON WHILE MDW
SHOULD PREVAIL WITH E OR SE WINDS THROUGHOUT THE AFTERNOON.
WINDS WILL SETTLE LIGHT SSW AFTER SUNSET, THEN VEER WNW WITH
GUSTS AROUND 20 KNOTS OR HIGHER BEHIND THE COLD FRONT SATURDAY
MORNING AND AFTERNOON.
KLUBER
LOT WATCHES/WARNINGS/ADVISORIES
IL...NONE.
IN...NONE.
LM...NONE.
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