220  
FXUS63 KILX 160508  
AFDILX  
 
AREA FORECAST DISCUSSION  
NATIONAL WEATHER SERVICE LINCOLN IL  
1208 AM CDT SUN AUG 16 2026  
   
KEY MESSAGES
 
 
- FLOODING CONTINUES ACROSS PORTIONS OF CENTRAL IL IN A CORRIDOR  
FROM FULTON AND SOUTHERN KNOX COUNTY TO VERMILION COUNTY DUE  
TO 4 TO 7 INCHES OF RAIN THAT FELL OVERNIGHT.  
 
- ADDITIONAL CLUSTERS OF THUNDERSTORMS ARE LIKELY TONIGHT INTO  
SUNDAY MORNING, WITH ISOLATED AFTERNOON THUNDERSTORMS POSSIBLE  
SUNDAY AFTERNOON. STORMS HAVE THE POTENTIAL TO PRODUCE LOCALLY  
DAMAGING WINDS. SPC HAS A MARGINAL (LEVEL 1 OF 5) RISK OF  
SEVERE WEATHER.  
 
- THE HEAT AND HUMIDITY REMAIN A CONCERN THIS WEEKEND, WITH THE  
HOTTEST CONDITIONS SOUTH OF I-70.  
 

 
   
DISCUSSION
 
 
ISSUED AT 156 PM CDT SAT AUG 15 2026  
 
IN THE WAKE OF WIDESPREAD THUNDERSTORM ACTIVITY THIS MORNING,  
HEAT HAS ONCE AGAIN BEEN TEMPERED OVER MUCH OF THE AREA WITH  
SOME LATE AFTERNOON RECOVERY EXPECTED TO BRING TEMPERATURES BACK  
UP TO THE LOW 90S BY AFTERNOON IN A CORRIDOR FROM JACKSONVILLE  
TO ROBINSON, WITH HEAT INDEX LIKELY TO REACH AROUND 105 SOUTH OF  
I-70 AS A WARM FRONT LIFTS NORTHWARD THROUGH THE AREA. MID TO  
UPPER 80S CAN BE EXPECTED TO THE NORTH.  
 
A FEW SHOWERS REMAIN IN THIS FRONTAL ZONE, WHERE PERHAPS A FEW  
THUNDERSTORMS COULD DEVELOP THIS AFTERNOON AS DIURNAL  
DESTABILIZATION GRADUALLY TAKES PLACE.  
 
TONIGHT, A COLD FRONT WILL APPROACH FROM THE NORTHWEST, WITH  
WARM ADVECTION AHEAD OF THE FRONT PROMOTING ANOTHER CLUSTER OR  
TWO OF THUNDERSTORMS. AREAS OF SIGNIFICANT PRECIPITATION ARE  
POSSIBLE, ALTHOUGH MUCH LESS LIKELY THAN LAST NIGHT. THE  
LOCATION OF ANY HEAVY PRECIPITATION SWATHS REMAINS TOO UNCERTAIN  
FOR A FLOOD WATCH AT THIS POINT, BUT WE WILL CONTINUE TO  
EVALUATE ANY CORRIDORS FOR POTENTIAL WATCH ISSUANCE. IF EXPECTED  
HEAVY PRECIPITATION CORRIDORS LINE UP WELL WITH LAST NIGHT'S  
HEAVY PRECIPITATION FROM FULTON TO VERMILION COUNTY THESE WOULD  
BE FAVORABLE FOR RENEWED FLOODING. 12Z HIGH-RES AVERAGE MODEL  
GUIDANCE POINTS TO A 1.5 TO 1.5 INCH CORRIDOR NORTH OF PEORIA  
AND BLOOMINGTON, ALTHOUGH THERE REMAIN CONSIDERABLE RUN-TO-RUN  
AND MODEL-TO-MODEL DISCREPANCIES. SPC CONTINUES A MARGINAL RISK  
FOR LOCALLY DAMAGING WINDS WITH THUNDERSTORMS BOTH TONIGHT AND  
SUNDAY AS THESE STORMS MOVE ACROSS CENTRAL IL AND SOME AFTERNOON  
THUNDERSTORMS AS DIURNAL DESTABILIZATION TAKES PLACE AND THE  
COLD FRONT LINGERS OVER THE SOUTHEAST HALF OF CENTRAL IL.  
 
A COUPLE OF DRY DAYS ARE FORECAST MONDAY AND TUESDAY BEHIND  
SUNDAY'S FRONT, THEN ANOTHER COLD FRONT MIDWEEK WILL BRING THE  
NEXT CHANCE FOR THUNDERSTORMS.  
 
TEMPERATURES WILL REMAIN QUITE WARM AND HUMID FOR CENTRAL IL AS  
2 INCH PRECIPITABLE WATER VALUES KEEP DEWPOINTS WELL INTO THE  
70S AND HIGHS REACH THE 80S, TO LOWER 90S SOUTH OF I-70. A HEAT  
ADVISORY CONTINUES FOR AREAS SOUTH OF I-70 UNTIL SUNDAY EVENING  
AS HEAT INDEX VALUES WILL NEAR 105 EACH AFTERNOON UNTIL THEN.  
HIGHS WILL BE IN THE 80S ACROSS THE AREA MONDAY THROUGH  
TUESDAY, THEN THE MIDWEEK FRONT WILL CONTINUE TO LOWER  
TEMPERATURES FOR LATE IN THE WEEK, WITH SOME UPPER 70S POSSIBLE.  
 

 
   
AVIATION /06Z TAFS THROUGH 06Z MONDAY/
 
 
ISSUED AT 1208 AM CDT SUN AUG 16 2026  
 
ANOTHER ROUND OF TSRA IS EXPECTED LATE TONIGHT, WITH THE HIGHEST  
PROBABILITIES SHIFTING SOUTH TO KSPI-KDEC-KCMI WHERE TEMPO  
GROUPS ARE FORECAST AND PROB30 FARTHER NORTH. A PERIOD OF MVFR  
CEILINGS IS FAVORED AT KPIA-KBMI SUNDAY MORNING. LIGHT SOUTHWEST  
WINDS TONIGHT WILL VEER WEST TO NORTHWEST ON SUNDAY WITH THE  
PASSAGE OF A COOL FRONT.  
 

 
   
ILX WATCHES/WARNINGS/ADVISORIES
 
 
FLOOD WATCH UNTIL 10 AM CDT THIS MORNING FOR ILZ027>031-  
036>038-043>046.  
HEAT ADVISORY UNTIL 10 AM CDT THIS MORNING FOR ILZ066>068-  
071>073.  
 

 
 

 
 
KEY MESSAGES...COPPLE  
DISCUSSION...37  
AVIATION...25  
 
CLICK HERE TO GO TO PREVIOUS BULLETINS.

The Nexlab IL Page Main Text Page