826  
FXUS63 KILX 221419  
AFDILX  
 
AREA FORECAST DISCUSSION  
NATIONAL WEATHER SERVICE LINCOLN IL  
919 AM CDT TUE SEP 22 2026  
   
KEY MESSAGES
 
 
- NO SIGNIFICANT WEATHER IS ANTICIPATED ACROSS CENTRAL ILLINOIS  
OVER THE NEXT WEEK.  
 

 
   
UPDATE
 
 
ISSUED AT 919 AM CDT TUE SEP 22 2026  
 
LATEST WATER VAPOR IMAGERY SHOWS THE UPPER LOW NEAR CEDAR RAPIDS  
IA. EXTENSIVE AREA OF SHOWERS HAS DEVELOPED ALONG THE SOUTHEAST  
FLANK OF THE CIRCULATION, EXTENDING FROM WEST CENTRAL ILLINOIS  
INTO SOUTHERN WISCONSIN. MORNING CAM'S ARE STARTING TO GET A  
BETTER HANDLE ON THIS ACTIVITY, THOUGH THEY DON'T REALLY SHOW  
ANY SIGNIFICANT EASTWARD PUSH JUST YET. POP'S HAVE BEEN UPDATED  
TO INCREASE CHANCES ACROSS AREAS NORTHWEST OF I-55 THROUGH THE  
MORNING. WHILE SOME SPRINKLES WILL OCCUR ALONG THE EASTERN EDGE,  
THESE SHOULD DIMINISH AS CEILINGS RISE.  
 
LARGE AREA OF STRATOCUMULUS IS IN PLACE, WITH SOME BRIEF EROSION  
TAKING PLACE THE LAST COUPLE HOURS NEAR CHAMPAIGN AND DANVILLE.  
THIS SHOULD FILL IN SOON AS ANOTHER STRATOCUMULUS DECK ADVECTS  
WESTWARD. TEMPERATURES HAVE BEEN RUNNING A BIT BELOW EARLIER  
PROJECTIONS DUE TO THE PERSISTENT CLOUDS, AND HIGH TEMPERATURES  
HAVE BEEN BROUGHT DOWN A COUPLE DEGREES.  
 

 
   
DISCUSSION
 
 
ISSUED AT 315 AM CDT TUE SEP 22 2026  
 
07Z/2AM SURFACE ANALYSIS SHOWS A 1032MB HIGH ANCHORED OVER  
ONTARIO/QUEBEC WHILE A STATIONARY FRONTAL BOUNDARY IS DRAPED  
FROM THE SOUTHERN APPALACHIANS TO TEXAS. DESPITE SYNOPTIC  
SUBSIDENCE AND A DRYING E/NE FLOW FROM THE GREAT LAKES, AMPLE  
CLOUD COVER REMAINS LOCKED IN PLACE ACROSS THE MIDWEST EARLY  
THIS MORNING. THE LATEST IR SATELLITE IMAGERY SHOWS A FEW BREAKS  
IN THE LOW OVERCAST...MOST NOTABLY ALONG/JUST SOUTH OF I-70 AND  
ALONG I-55 FROM CHICAGO TO LINCOLN. GIVEN CONTINUED E/NE FLOW,  
MOST CAMS SHOW WIDESPREAD CLOUD COVER UPSTREAM ACROSS INDIANA  
SPILLING BACK WESTWARD ACROSS MUCH OF CENTRAL ILLINOIS AS THE  
MORNING PROGRESSES. THE EXCEPTION WILL BE ALONG/WEST OF I-55  
WHERE PARTIAL CLEARING APPEARS LIKELY. AS AN UPPER-LEVEL LOW  
EVIDENT ON WATER VAPOR IMAGERY OVER EASTERN IOWA SLOWLY TRACKS  
EASTWARD, A FEW VERY LIGHT SHOWERS OR SPRINKLES WILL BE  
POSSIBLE. WHILE THE NAM SUGGESTS MUCAPES WILL REMAIN BELOW  
100J/KG, THINK THIS MAY BE A BIT UNDERDONE GIVEN THE EXPECTED  
BREAKS IN THE OVERCAST. WITH SUFFICIENT MOISTURE/FORCING AND  
RRFS 700-500MB LAPSE RATES OF AROUND 6-7C/KM, HAVE MENTIONED  
ISOLATED SHOWERS/SPRINKLES ALONG/NORTH OF THE I-72 CORRIDOR  
THROUGH THE AFTERNOON. HIGH TEMPERATURES WILL MOSTLY BE IN THE  
MIDDLE TO UPPER 60S, WITH LOWER 70S ALONG/SOUTH OF I-70.  
 
WHILE SURFACE RIDGING WILL BUILD INTO THE REGION TONIGHT,  
PERSISTENT BOUNDARY LAYER MOISTURE BENEATH THE SUBSIDENCE  
INVERSION WILL CREATE A CHALLENGING CLOUD COVER FORECAST. WHILE  
PREVIOUS THINKING SUGGESTED PARTLY TO MOSTLY CLEAR SKIES AND  
GOOD RADIATIONAL COOLING CONDITIONS OVERNIGHT, THE LATEST DATA  
INDICATES THE LOW CLOUD COVER REMAINING IN PLACE AND/OR  
SPREADING BACK WESTWARD ACROSS MUCH OF THE KILX CWA. AS A  
RESULT, THINK PARTIAL CLEARING WILL BE LIMITED TO THE ILLINOIS  
RIVER VALLEY WITH CLOUDY SKIES FURTHER EAST. DUE TO THE  
INCREASED CLOUD COVER, HAVE RAISED LOW TEMPERATURES BY A FEW  
DEGREES...RANGING FROM THE LOWER 50S NORTHWEST OF THE ILLINOIS  
RIVER TO THE UPPER 50S ALONG/EAST OF I-57.  
 
MOSTLY CLOUDY CONDITIONS WITH BELOW NORMAL TEMPERATURES IN THE  
UPPER 60S AND LOWER 70S WILL CONTINUE INTO WEDNESDAY BEFORE  
INCREASING AMOUNTS OF SUNSHINE SLOWLY PUSH READINGS BACK INTO  
THE LOWER TO MIDDLE 70S BY FRIDAY/SATURDAY. AFTER THAT, A  
BLOCKING PATTERN WILL DEVELOP ACROSS THE EASTERN CONUS FEATURING  
A DEEP UPPER LOW OVER THE MID-ATLANTIC REGION AND A RIDGE OF  
HIGH PRESSURE FURTHER WEST ACROSS THE MIDWEST. AS A RESULT, IT  
APPEARS A RETURN TO ABOVE NORMAL TEMPERATURES IN THE 80S IS IN  
STORE FOR CENTRAL ILLINOIS BY EARLY NEXT WEEK.  
 

 
   
AVIATION /12Z TAFS THROUGH 12Z WEDNESDAY/
 
 
ISSUED AT 543 AM CDT TUE SEP 22 2026  
 
MVFR CEILINGS BLANKET CENTRAL ILLINOIS EARLY THIS MORNING:  
HOWEVER, DRIER BOUNDARY LAYER AIR AND HIGHER CEILINGS REMAIN  
POISED JUST TO THE NORTHEAST AND WILL GRADUALLY FILTER INTO THE  
AREA LATER THIS MORNING. CAMS APPEAR TO BE A LITTLE TOO  
AGGRESSIVE WITH THE IMPROVING CEILINGS, SO HAVE DELAYED ONSET OF  
VFR AT ALL SITES BY A COUPLE OF HOURS. AS A RESULT, HAVE RAISED  
THE CLOUD DECK TO VFR AT THE I-74 TERMINALS BETWEEN 14Z AND 16Z,  
THEN FURTHER S/SW TO KDEC/KSPI BY 17Z/18Z. CLOUDS WILL TEMPORARILY  
SCATTER AT TIMES TODAY, BUT SKIES WILL GENERALLY REMAIN MOSTLY  
CLOUDY. AFTER SUNSET, THE CONTINUED E/NE BOUNDARY LAYER FLOW  
WILL LIKELY ALLOW LOW CLOUDS TO MAKE A RETURN FROM THE EAST.  
HRRR/RAP SUGGEST CEILINGS LOWERING BACK TO MVFR AT KCMI BY  
AROUND 00Z, THEN FURTHER WEST TO A KBMI TO KDEC LINE LATER IN  
THE EVENING. WINDS WILL REMAIN NE AT 10-15KT THROUGH THE ENTIRE  
12Z TAF PERIOD.  
 

 
   
ILX WATCHES/WARNINGS/ADVISORIES
 
 
NONE.  
 

 
 

 
 
KEY MESSAGES...BARNES  
UPDATE...GEELHART  
DISCUSSION...BARNES  
AVIATION...BARNES  
 
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