639  
FXUS63 KILX 230501  
AFDILX  
 
AREA FORECAST DISCUSSION  
NATIONAL WEATHER SERVICE LINCOLN IL  
1201 AM CDT WED SEP 23 2026  
   
KEY MESSAGES
 
 
- LINGERING SHOWERS NORTHWEST OF THE ILLINOIS RIVER SHOULD  
DIMINISH BY LATE AFTERNOON.  
 
- OVERALL, A TRANQUIL WEATHER PATTERN WILL BE IN PLACE THROUGH  
THE WEEKEND, WITH TEMPERATURES FAIRLY TYPICAL FOR THE  
BEGINNING OF AUTUMN.  
 

 
   
DISCUSSION
 
 
ISSUED AT 100 PM CDT TUE SEP 22 2026  
 
FALL BEGINS IN A FEW HOURS, AND COOLER TEMPERATURES AND BRISK  
NORTHWEST WINDS GIVE IT THAT FALL FEELING. WITH SHOWERS  
PERSISTING NORTHWEST OF THE ILLINOIS RIVER EARLY THIS AFTERNOON,  
TEMPERATURES IN THAT AREA HAVE BEEN CONFINED TO THE UPPER 50S.  
SOME BREAKS IN THE CLOUDS OVER EAST CENTRAL ILLINOIS HAVE  
ALLOWED TEMPERATURES TO REACH NEAR 70 IN A FEW AREAS. OVERALL  
THE HIGH-RES MODELS HAVE NOT HANDLED THIS RAIN ESPECIALLY WELL,  
THOUGH THE HRRR SUGGESTS IT WILL PERSIST FOR A FEW MORE HOURS.  
 
WATER VAPOR IMAGERY SHOWS AN UPPER LOW CENTERED JUST SOUTHWEST  
OF DUBUQUE, AND THIS LOW SHOULD TIGHTEN UP A BIT AS IT DROPS  
SOUTHEAST INTO THE OHIO VALLEY BY LATE WEDNESDAY MORNING.  
ANOTHER SLUG OF LOWER CLOUDS WILL ADVECT IN FROM THE EAST  
BEGINNING THIS EVENING WITHIN THE CIRCULATION, PERSISTING  
THROUGH MUCH OF WEDNESDAY. SOUNDINGS SHOW A FAIRLY PROMINENT DRY  
LAYER BETWEEN 5-8KFT, SO ANY PRECIPITATION WOULD PROBABLY BE  
MORE IN THE FORM OF DRIZZLE OR SPRINKLES. BEST CHANCES WOULD BE  
IN EASTERN ILLINOIS, AS SOUNDINGS FURTHER WEST HAVE A SHALLOWER  
DEPTH OF MOISTURE IN THE LOWER LEVELS. WITH THE PERSISTENT  
CLOUDS, TEMPERATURES SHOULD BE HELD BACK A BIT, THOUGH SOME  
LOWER 70S CAN'T BE RULED OUT ESPECIALLY WHERE SOME SUNSHINE DOES  
OCCUR.  
 
OVERALL, THE LONGER RANGE OUTLOOK LOOKS RATHER TAME, AS A  
DEVELOPING NOR'EASTER OFF THE EAST COAST SLOWS WEST-EAST  
PROGRESSION OF ANY STORM SYSTEMS THROUGH MUCH OF THE WEEKEND.  
SPRAWLING HIGH PRESSURE OVER SOUTHERN QUEBEC, NORTH OF THE  
STORM, WILL KEEP US IN AN EASTERLY FLOW, KEEPING ANY  
SIGNIFICANT WARMING TREND AT BAY THROUGH THE WEEKEND. HIGH  
TEMPERATURES. IT MAY TAKE UNTIL EARLY NEXT WEEK TO FULLY  
DISLODGE THIS EASTERN LOW, AT WHICH WE START GETTING MORE OF A  
SOUTHERLY WIND FLOW. LREF PROBABILITIES OF HIGH TEMPERATURES  
GREATER THAN 80 DEGREES RANGE FROM 30-60% MONDAY AND TUESDAY  
FROM WEST CENTRAL TO SOUTHEAST ILLINOIS.  
 

 
   
AVIATION /06Z TAFS THROUGH 06Z THURSDAY/
 
 
ISSUED AT 1200 AM CDT WED SEP 23 2026  
 
HIGH PRESSURE WILL REMAIN ANCHORED JUST NORTH OF THE GREAT  
LAKES THROUGH THE PERIOD RESULTING IN A MODEST NORTHEAST BREEZE  
AROUND 10 KT ACROSS CENTRAL ILLINOIS. MVFR CEILINGS ARE IN  
PLACE ACROSS EAST CENTRAL ILLINOIS AND INDIANA, SPREADING WEST  
OVERNIGHT. OVER NORTHEAST ILLINOIS, CEILINGS ARE IN PLACE BUT  
ARE JUST HIGH ENOUGH TO REMAIN VFR. PIA HAS THE GREATEST CHANCE  
OF STAYING IN THESE SLIGHTLY HIGHER CEILINGS WHILE CONFIDENCE  
IS HIGHER FOR MVFR CEILINGS AT THE REMAINING TERMINALS.  
CONDITIONS SHOULD SCATTER/LIFT BACK TO VFR FROM THE WEST  
GRADUALLY THROUGH THE DAY WEDNESDAY. THAT BEING SAID, THERE MAY  
NOT BE ENOUGH DAYLIGHT FOR CONDITIONS AT DEC AND CMI TO IMPROVE  
THAT FAR EAST, THUS THEY ARE FORECAST TO REMAIN MVFR THROUGH  
THE PERIOD.  
 

 
   
ILX WATCHES/WARNINGS/ADVISORIES
 
 
NONE.  
 

 
 

 
 
KEY MESSAGES...GEELHART  
DISCUSSION...GEELHART  
AVIATION...DEUBELBEISS  
 
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