717  
FXUS63 KILX 132324  
AFDILX  
 
AREA FORECAST DISCUSSION  
NATIONAL WEATHER SERVICE LINCOLN IL  
624 PM CDT THU AUG 13 2026  
   
KEY MESSAGES
 
 
- FLASH FLOODING IS A CONCERN ALONG AND NORTH OF THE I-74  
CORRIDOR OVERNIGHT. HREF PROBABILITIES OF MORE THAN 2 INCHES  
OF RAIN ARE 30-50% IN THIS AREA, ALTHOUGH SOME LOCAL TOTALS  
OVER 3 INCHES ARE POSSIBLE.  
 
- HEAT INDEX VALUES OF 100 TO 105 DEGREES WILL CONTINUE INTO THE  
WEEKEND EACH AFTERNOON, IN AREAS NEAR AND SOUTH OF I-70. THE  
HEAT IS EXPECTED TO SPREAD NORTHWARD ACROSS THE FORECAST AREA  
BY SATURDAY.  
 

 
   
DISCUSSION
 
 
ISSUED AT 235 PM CDT THU AUG 13 2026  
 
MCS THAT TRACKED OUT OF IOWA EARLIER TODAY INTENSIFIED AGAIN AS  
IT CROSSED THE PEORIA METRO, PRODUCING WINDS AROUND 70 MPH AND  
EXTENSIVE DAMAGE IN BLOOMINGTON. CLUSTER OF STORMS HAS REACHED  
THE CHAMPAIGN AREA THIS HOUR, WITH THE TRAILING OUTFLOW  
EXTENDING WEST THROUGH SPRINGFIELD. STORMS ARE RIDING ALONG A  
TIGHT GRADIENT OF CAPE AND SHOULD EXIT THE FORECAST AREA IN THE  
NEXT FEW HOURS.  
 
NEXT MCS IS EXPECTED TO BEGIN DEVELOPING THIS EVENING CLOSER TO  
THE WARM FRONT FROM IOWA TO NORTHERN INDIANA, THEN SINK  
SOUTHWARD OVERNIGHT. PRECIPITABLE WATER VALUES OVER 2 INCHES  
PERSIST THROUGH THE NIGHT, AND SOME OF THE NORTHERN PARTS OF OUR  
FORECAST AREA HAVE SEEN A FEW INCHES OF RAIN SINCE YESTERDAY.  
HREF PMM PRECIP ESTIMATES SUGGEST 1.5-2 INCHES OF RAIN IN 6  
HOURS BETWEEN MIDNIGHT AND SUNRISE, AND NO CHANGES ARE BEING  
MADE TO THE FLOOD WATCH AT THIS TIME. SOUTH HALF OF THE FORECAST  
AREA HAS A GOOD CHANCE OF REMAINING DRY UNTIL CLOSER TO  
DAYBREAK.  
 
HEAT FORECASTS REMAIN A CONCERN AS WELL. LATEST GUIDANCE  
SUGGESTS 100-105 HEAT INDEX COULD REACH AS FAR NORTH AS A  
RUSHVILLE-PARIS LINE TOMORROW, BUT THE EXTENT OF THE LINGERING  
RAIN/CLOUD SHIELD INTRODUCES SOME UNCERTAINTY AS TO WHETHER OR  
NOT TO EXPAND THE HEAT ADVISORY. CURRENT INCLINATION IS TO LEAVE  
IT IN PLACE AND ALLOW THE NEXT SHIFT TO EXPAND IT, ONCE THE  
TIMING AND TRACK OF THE MCS BECOMES MORE CERTAIN. AN EXPANSION  
FOR THE ENTIRE FORECAST AREA APPEARS MORE LIKELY FOR SATURDAY.  
 
A QUICK LOOK AT THE EXTENDED FORECAST -- UPPER PATTERN BECOMES  
MORE ZONAL FOR A TIME AS HIGH PRESSURE SPRAWLS MORE WEST-EAST  
ACROSS THE SOUTHERN U.S. GETTING INTO EARLY NEXT WEEK, RIDING  
AMPLIFIES WEST OF THE ROCKIES AS A STRONG UPPER TROUGH SWINGS  
ACROSS THE CANADIAN PRAIRIES AND THE NORTH CENTRAL U.S. IMPACTS  
FROM THAT IN OUR AREA WOULD BE MORE LIKELY TOWARD THE MIDDLE OF  
NEXT WEEK. A COUPLE DAYS OF COOLER TEMPERATURES ARE LIKELY  
EARLY NEXT WEEK, BEFORE WARMING BEGINS AGAIN.  
 

 
   
AVIATION /00Z TAFS THROUGH 00Z SATURDAY/
 
 
ISSUED AT 623 PM CDT THU AUG 13 2026  
 
STORMS FROM EARLIER THIS AFTERNOON HAVE CLEARED THE TERMINALS  
LEAVING VFR CONDITIONS AND EAST/SOUTHEAST WINDS ACROSS CENTRAL  
ILLINOIS. IFR CEILINGS ARE IN PLACE JUST NORTH OF PIA/BMI THIS  
EVENING AND EXPECTED TO EXPAND SOUTH TOWARDS THE I-74 CORRIDOR  
OVERNIGHT WHILE MVFR CEILINGS DEVELOP ACROSS THE REMAINDER OF  
CENTRAL IL BY LATE TONIGHT. MEANWHILE, ADDITIONAL SHOWERS AND  
STORMS WILL FORM TONIGHT ALONG A STATIONARY FRONT OVER THE  
REGION AND CONTINUE INTO FRIDAY MORNING. CONFIDENCE IN  
PLACEMENT AND TIMING REMAINS LOW AT THIS TIME BUT ARE GENERALLY  
FAVORED BETWEEN I-72 AND I-80.  
 

 
   
ILX WATCHES/WARNINGS/ADVISORIES
 
 
FLOOD WATCH THROUGH FRIDAY MORNING FOR ILZ027>031-037-038-045-  
046.  
HEAT ADVISORY UNTIL 8 PM CDT SUNDAY FOR ILZ066>068-071>073.  
 

 
 

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