763
FXUS63 KLOT 151109
AFDLOT
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE CHICAGO/ROMEOVILLE, IL
609 AM CDT MON SEP 15 2025
KEY MESSAGES
- WARM AND DRY CONDITIONS ARE EXPECTED THROUGH THE WORK WEEK.
- PERIODIC SHOWER AND THUNDERSTORM CHANCES RETURN TOWARD THE END
OF THE WEEK (20-30%).
DISCUSSION
ISSUED AT 245 AM CDT MON SEP 15 2025
AN OVERALL QUIESCENT PATTERN IS IN PLACE ACROSS THE REGION WITH
AMPLIFIED UPPER RIDGING ACROSS THE WESTERN GREAT LAKES REGION
ATOP A CLOSED UPPER LOW IN THE SOUTHEAST (A PSEUDO-REX BLOCK
PATTERN). THIS WILL ALLOW UNSEASONABLY WARM TEMPERATURES TO
PREVAIL THROUGH THE REST OF THE WORK WEEK WITH HIGH TEMPERATURES
IN THE 80S TO NEAR 90 (WARMEST TOWARD WESTERN AND CENTRAL
ILLINOIS). RELATIVELY WEAK SURFACE FLOW AMIDST EXPANSIVE SURFACE
HIGH PRESSURE SHOULD ALLOW DAILY LAKE BREEZES TO PUSH INLAND
HOLDING TEMPERATURES MAINLY IN THE 70S NEAR THE LAKESHORE. THIS
SHOULD ALSO HELP KEEP ANY SHOWER/STORM ACTIVITY WEST OF THE
LOCAL AREA FOR THE MAJORITY OF THE WORK WEEK.
ENSEMBLE GUIDANCE HAS ALSO TRENDED A BIT SLOWER WITH THE BREAK
DOWN OF THE UPPER RIDGE/BLOCKING PATTERN LATER IN THE WEEK WITH
MOST OF THE AREA REMAINING DRY THROUGH THE DAY ON FRIDAY AND
FURTHER SLOWING COULD OCCUR WITH LATER UPDATES. EVENTUALLY THE
WESTERN TROUGH (AND/OR POTENTIAL CUT-OFF LOW) WILL SHIFT EAST
TOWARD AND OVER THE AREA LEADING TO PERIODIC SHOWER AND
THUNDERSTORM CHANCES OVER THE WEEKEND INTO EARLY NEXT WEEK. THIS
WILL BE PAIRED WITH COOLER MORE SEASONABLE TEMPERATURES IN THE
70S.
PETR
AVIATION /12Z TAFS THROUGH 18Z TUESDAY/
ISSUED AT 609 AM CDT MON SEP 15 2025
NO MAJOR FORECAST CONCERNS ARE EXPECTED THROUGH THE TAF PERIOD
AS A RIDGE OF HIGH PRESSURE WILL REMAIN IN PLACE OVER THE GREAT
LAKES. THE CURRENT SOUTHEAST WINDS WILL BECOME MORE EASTERLY
LATER THIS MORNING WITH SPEEDS REMAINING GENERALLY IN THE 5-8 KT
RANGE. HOWEVER, THERE IS THE POTENTIAL FOR A LAND BREEZE TO
DEVELOP TONIGHT WHICH MAY TURN WINDS MORE NORTH-NORTHEASTERLY AT
ORD AND MDW BEFORE THEY TURN BACK EASTERLY TUESDAY MORNING.
WHILE MOST GUIDANCE KEEPS WINDS EAST OF NORTH TONIGHT, CANNOT
COMPLETELY RULE OUT A PERIOD OF NORTHWEST WINDS ESPECIALLY AT
ORD. OTHERWISE, MOSTLY CLEAR SKIES WILL PREVAIL ASIDE FROM A
PASSING CIRRUS CLOUD.
YACK
LOT WATCHES/WARNINGS/ADVISORIES
IL...NONE.
IN...NONE.
LM...NONE.
VISIT US AT WEATHER.GOV/CHICAGO
CLICK HERE TO GO TO PREVIOUS BULLETINS.
Main Text Page