013
FXUS63 KLOT 161739
AFDLOT
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE CHICAGO/ROMEOVILLE, IL
1239 PM CDT TUE SEP 16 2025
KEY MESSAGES
- WARM AND DRY CONDITIONS PERSIST THROUGH THE WORK WEEK.
- PERIODIC SHOWER AND THUNDERSTORM CHANCES RETURN THIS WEEKEND
INTO EARLY NEXT WEEK (20-40%).
DISCUSSION
ISSUED AT 305 AM CDT TUE SEP 16 2025
EXPANSIVE SURFACE HIGH PRESSURE ACROSS THE BROADER GREAT LAKES
REGION EARLY THIS MORNING HAS LED TO CONTINUED MOSTLY CLEAR
SKIES AND LIGHT AND VARIABLE TO CALM WINDS. RADIATIONAL COOLING
ACROSS INTERIOR NORTHERN ILLINOIS MAY LEAD TO PATCHY SHALLOW FOG
DEVELOPMENT THROUGH DAYBREAK BUT COVERAGE SHOULD REMAIN MUCH
LOWER THAN SEEN OVER THE WEEKEND GIVEN OVERALL DRIER LOW-LEVELS.
A BLOCKY UPPER-LEVEL FLOW PATTERN ACROSS THE EASTERN CONUS WILL
CONTINUE TO SUPPORT QUIET WEATHER CONDITIONS ACROSS OUR AREA
THROUGH THE WORK WEEK. 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 WILL ALLOW LAKE BREEZES TO PUSH INLAND EACH
AFTERNOON. 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, THE UPPER LEVEL RIDGE
BEGINS TO BREAK DOWN HEADING INTO THE WEEKEND AS A WESTERN
TROUGH (AND/OR POTENTIAL CUT-OFF LOW) BEGINS TO SLIDE EASTWARD
TOWARDS THE GREAT LAKES. THIS WILL LEAD TO INCREASING CHANCES
FOR PERIODIC SHOWERS AND THUNDERSTORMS OVER THE WEEKEND INTO
EARLY NEXT WEEK.
PETR/KJB
AVIATION /18Z TAFS THROUGH 00Z THURSDAY/
ISSUED AT 1238 PM CDT TUE SEP 16 2025
VFR CONDITIONS ARE EXPECTED THROUGH MUCH OF THE PERIOD AS A
SURFACE HIGH PRESSURE RIDGE REMAINS DRAPED ACROSS THE AREA.
HOWEVER, MVFR BR AND/OR MIFG ARE EXPECTED TO DEVELOP AT OUTLYING
SITES (DPA, RFD, GYY) OVERNIGHT. HIGHER SURFACE MOISTURE FROM
LAKE-MODIFIED AIR MAY ALSO SUPPORT VFR BR AT ORD LATE TONIGHT
THROUGH SUNRISE WEDNESDAY.
WINDS WILL SETTLE ENE UP TO 10 KNOTS THIS AFTERNOON THROUGH
THIS EVENING. EXPECT WINDS TO BECOME CALM OR LIGHT AND VRB
OVERNIGHT, THOUGH THE VRB WINDS MAY FAVOR NORTH OR JUST WEST OF
NORTH AT ORD/MDW BEHIND A WEAK LAND BREEZE. ENE WINDS UP TO 10
KNOTS WILL RESUME BY LATE WEDNESDAY MORNING.
KLUBER
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