916  
FXUS63 KILX 161056  
AFDILX  
 
AREA FORECAST DISCUSSION  
NATIONAL WEATHER SERVICE LINCOLN IL  
556 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 YESTERDAY AND ADDITIONAL  
RAIN MOVING THROUGH THIS MORNING.  
 
- ADDITIONAL CLUSTERS OF THUNDERSTORMS ARE FORECAST AGAIN LATE  
THIS AFTERNOON INTO THE OVERNIGHT HOURS. SPC HAS A SLIGHT  
RISK (LEVEL 2 OF 5) SOUTH OF I-70 AND A MARGINAL RISK FOR  
AREAS EAST OF THE IL RIVER VALLEY FOR DAMAGING WINDS.  
 
- COOLER AND LESS ACTIVE WEATHER IS ON DECK AFTER TODAY. MONDAY  
WILL HAVE HIGHS IN THE 80S AND DRY WEATHER IN PLACE.  
 

 
   
DISCUSSION
 
 
ISSUED AT 153 AM CDT SUN AUG 16 2026  
 
TONIGHT MORE SHOWERS AND STORMS WILL BE MOVING ACROSS CENTRAL IL.  
THE MAIN CONCERN IS THE FLASH FLOODING RISK. WPC HAS A SMALL AREA OF  
EASTERN IL IN A MODERATE RISK (LEVEL 3 OF 4) AND NEAR AND NORTH OF I-  
72 IN A SLIGHT RISK (LEVEL 2 OF 4) FOR EXCESSIVE RAINFALL FOR THE  
OVERNIGHT HOURS (VALID UNTIL 12Z). THE 00Z SOUNDING SHOWS THE  
ENVIRONMENT HAVING PWATS OF 2.2-2.4 INCHES AGAIN. FLOODING IS  
ALREADY ONGOING IN MANY PLACES, LEFT OVER FROM LAST NIGHT'S EVENT.  
IT WILL NOT TAKE MUCH TO EXACERBATE THE SITUATION OVERNIGHT IF THE  
NEW CONVECTION DECIDES TO SET UP OVER THAT STRIPE OF CENTRAL IL  
(FULTON CO TO VERMILION CO) AGAIN. LPMM IS SUGGESTING THAT WE COULD  
SEE ANOTHER LOCALIZED STRIPE OF 4-8 INCHES SOMEWHERE IN THE AREA  
NORTH OF I-72.  
 
THERE IS A SLIGHT RISK (LEVEL 2 OF 5) SOUTH OF I-70 AND A MARGINAL  
RISK FOR AREAS EAST OF THE IL RIVER VALLEY FOR DAMAGING WINDS AGAIN  
TODAY. THE NAMNEST IS DEPICTING A MORE WIDELY DRY, NEARLY NO  
ACTIVITY, SOLUTION. THE HRRR HAS AN AREA OF CONVECTION DEVELOPING  
LATE AFTERNOON IN WEST CENTRAL IL, PROGRESSING EASTWARD INTO THE  
OVERNIGHT HOURS WITH THE COLD FRONT. AFTER HOW MUCH RAIN NORTH OF I-  
70 HAS RECEIVED OVER THE LAST SEVERAL DAYS, THE HOPE IS FOR THE  
DRIER SOLUTION, BUT PLAN FOR THE STORMIER SOLUTION. WITH THE HRRR  
VERSION OF EVENTS, IT IS SHOWING POCKETS OF 2-4 INCHES OF RAINFALL  
FROM 21Z-09Z TODAY INTO TOMORROW. THE GOOD NEWS THOUGH WOULD BE THAT  
IF THIS ACTIVITY WERE TO DEVELOP, IT WOULD BE FAIRLY PROGRESSIVE AND  
LESS OF A TRAINING SET UP, UNLIKE PREVIOUS DAYS.  
 
TEMPERATURES REMAIN HOT AND HUMID FOR ONE MORE DAY. THE HEAT  
ADVISORY FOR SOUTH OF I-70 IS VALID THROUGH 8PM (01Z) THIS EVENING.  
HEAT INDICES OF 100-105 DEGREES ARE EXPECTED.  
 
A BRIEF BREAK IN THE ACTIVE WEATHER AND THE HEAT IS LOOKING LIKELY  
FOR MONDAY INTO TUESDAY. A HIGH PRESSURE CENTER WILL SET UP OVER THE  
UPPER MISSISSIPPI VALLEY / GREAT LAKES REGION BEHIND A COLD FRONT  
THAT WILL MOVE THROUGH CENTRAL IL DURING THE DAY TODAY. TEMPERATURES  
STARTING MONDAY INTO MUCH OF THE NEXT WEEK WILL BE MAINLY IN THE  
UPPER 70S TO 80S FOR HIGHS AND 60S TO LOW 70S FOR LOWS.  
 
MORE SHOWERS AND THUNDERSTORM RE-ENTER THE FORECAST BY TUESDAY  
EVENING INTO WEDNESDAY. SPC HAS CENTRAL IL IN A MARGINAL RISK FOR  
SEVERE WEATHER FOR TUESDAY WEST OF I-55, WHICH WOULD BE FOR THE LATE  
DAY CONVECTION. THERE ARE ADDITIONAL CHANCE FOR RAIN THROUGH  
THURSDAY BEFORE RETURNING TO A MOSTLY DRY FORECAST INTO THE  
LATE WEEK.  
 

 
   
AVIATION /12Z TAFS THROUGH 12Z MONDAY/
 
 
ISSUED AT 556 AM CDT SUN AUG 16 2026  
 
VFR CONDITIONS ARE EXPECTED OUTSIDE OF ANY HEAVY SHOWER OR  
THUNDERSTORM ACTIVITY. IF A HEAVIER SHOWER/STORM MOVES THROUGH A  
SITE THIS MORNING, MVFR CEILINGS/VISIBILITIES ARE POSSIBLE.  
LIGHT NORTHWESTERLY WINDS ARE EXPECTED THE ENTIRE PERIOD  
BECOMING CALM OVERNIGHT TONIGHT. ANOTHER ROUND OF STORMS ARE  
FORECAST FOR LATE THIS EVENING INTO THE OVERNIGHT HOURS, BUT  
TIME/LOCATION ARE UNCERTAIN SO PROB30 WAS USED BETWEEN 02Z TO  
08Z.  
 

 
   
ILX WATCHES/WARNINGS/ADVISORIES
 
 
FLOOD WATCH UNTIL 10 AM CDT THIS MORNING FOR ILZ027>031-  
036>038-043>046.  
HEAT ADVISORY UNTIL 8 PM CDT THIS EVENING FOR ILZ066>068-  
071>073.  
 

 
 

 
 
KEY MESSAGES...COPPLE  
DISCUSSION...COPPLE  
AVIATION...COPPLE  
 
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