853  
FXUS63 KILX 290455  
AFDILX  
 
AREA FORECAST DISCUSSION...UPDATED AVIATION  
NATIONAL WEATHER SERVICE LINCOLN IL  
1155 PM CDT SAT JUN 28 2025  
   
KEY MESSAGES
 
 
- VERY WARM AND HUMID CONDITIONS PERSIST THROUGH MONDAY, THEN A  
COLD FRONT WILL USHER IN SEASONABLE TEMPERATURES AND HUMIDITY  
LEVELS.  
 
- ISOLATED SHOWERS AND THUNDERSTORMS ARE POSSIBLE INTO EARLY  
EVENING SOUTH OF I-72. A BETTER CHANCE FOR PRECIP EXISTS AREA-  
WIDE LATE SUNDAY NIGHT INTO MONDAY (50-80% CHANCE) AS A COLD  
FRONT MOVES IN. A FEW STRONG TO SEVERE STORMS WITH GUSTY WINDS  
COULD OCCUR.  
 

 
   
UPDATE
 
 
ISSUED AT 617 PM CDT SAT JUN 28 2025  
 
ONLY NECESSARY CHANGE TO THE FORECAST THIS EVENING WAS THE  
ADDITION OF 15-30% POPS ALONG A NARROW CORRIDOR EXTENDING FROM  
ROUGHLY DECATUR TO ARTHUR WHERE DIFFERENTIAL HEATING ALONG THE  
REMNANTS OF AN OUTFLOW BOUNDARY HAS LED TO A FEW SHOWERS AND EVEN  
ONE BRIEF THUNDERSTORM OVER THE PAST 1-2 HOURS. WANING SURFACE  
HEATING SHOULD CAUSE THIS ACTIVITY TO WEAKEN AND EVENTUALLY  
DISSOLVE, MAINLY AFTER AROUND 7PM.  
 
BUMGARDNER  
 

 
   
DISCUSSION
 
 
ISSUED AT 245 PM CDT SAT JUN 28 2025  
 
A WEAK BOUNDARY LINGERED OVER CENTRAL PARTS OF IL/IN WITH ISOLATED  
CONVECTION SOUTH OF I-72. UNSTABLE AIRMASS OVER CENTRAL/SE IL WITH  
SB CAPES 2500-3500 J/KG SOUTH OF I-74 WHILE MLCAPES WERE 1-2K J/KG.  
PW VALUES WERE 1.5-1.9 INCHES FROM SHELBYVILLE TO PARIS SOUTH  
WHERE DEEPER TROPICAL MOISTURE WAS. MORE WIDESPREAD CONVECTION WAS  
OVER SOUTHERN IN INTO WESTERN HALF OF KY/TN AND SW OF ST LOUIS  
METRO OVER CENTRAL AND SOUTH CENTRAL MO INTO NORTH CENTRAL AR.  
VERY WARM AND HUMID CONDITIONS PREVAILED OVER CWA WITH TEMPS  
86-92F AND HEAT INDICES IN THE 90S, WITH SPI, DEC, LWV AND HUF  
REACHING 99 HEAT INDEX.  
 
ISOLATED CONVECTION WILL LINGER SOUTH OF I-72 UNTIL SUNSET, THOUGH  
SEVERE STORMS NOT EXPECTED. PATCHY FOG IS POSSIBLE AGAIN LATER  
TONIGHT AND EARLY SUNDAY MORNING SOUTH OF I-72. MUGGY LOWS IN THE  
LOWER 70S OVERNIGHT ACROSS THE CWA.  
 
ISOLATED TO SCATTERED CONVECTION TO REDEVELOP OVER CENTRAL IL ON  
SUNDAY FROM SW TO NE IN TROPICAL AIRMASS. VERY WARM AND HUMID  
AGAIN ON SUNDAY WITH HIGHS IN THE UPPER 80S TO AROUND 90F (WARMEST  
I-74 NORTH) AND HEAT INDICES PEAKING IN THE MID TO UPPER 90S. BETTER  
COVERAGE OF CONVECTION WILL BE DURING SUNDAY NIGHT INTO MONDAY AS  
COLD FRONT MOVES IN DURING MONDAY. SPC DAY2 OUTLOOK HAS MARGINAL  
RISK OF SEVERE STORMS SUNDAY NIGHT FOR DAMAGING WINDS OVER THE IL  
RIVER VALLEY IN NW CWA, WITH SLIGHT RISK OVER MUCH OF IOWA AND  
NORTH CENTRAL AND NW MO. SPC DAY3 HAS MARGINAL RISK OF SEVERE  
STORMS FOR DAMAGING WINDS FROM THE IL RIVER SE ON MONDAY AS COLD  
FRONT MOVES THROUGH. HIGHS MONDAY IN THE MID 80S CENTRAL IL AND  
UPPER 80S IN SOUTHEAST IL WITH HEAT INDICES 90-95F. CHANCE OF  
SHOWERS AND THUNDERSTORMS LINGERS SE OF I-55 MONDAY EVENING AND  
GOES LONGER IN THE EVENING MONDAY OVER SOUTHEAST IL.  
 
WEAK HIGH PRESSURE DRIFTS INTO THE AREA TUE NIGHT AND WED BRINGING  
DRY CONDITIONS WITH MORE SEASONABLE TEMPERATURES AND HUMIDITY  
LEVELS. HIGHS IN THE MID TO UPPER 80S TUE AND WED BUT DEWPOINTS  
LOWERING FROM 70S MONDAY TO 60S TUE AND WED.  
 
UPPER LEVEL RIDGE BUILDING BACK OVER THE EASTERN PLAINS AND MS  
RIVER VALLEY LATE NEXT WEEK TO BRING BACK SOME MORE HEAT AND  
HUMIDITY, THOUGH NOT QUITE AS HOT AS THIS PAST WEEK. HAVE ISOLATED  
CONVECTION CHANCES THU AND FRI AFTERNOON WITH 20-40% CHANCE OF  
SHOWERS AND THUNDERSTORMS NEXT SATURDAY. HIGHS IN THE UPPER 80S TO  
NEAR 90F THU, AROUND 90 FRI AND LOWER 90S NEXT SATURDAY AS HEAT  
INDICES CLIMB BACK INTO THE MID 90S TO NEAR 100F NEXT FRI/SAT.  
 
07  
 

 
   
AVIATION
 
(FOR THE 06Z TAFS THROUGH 06Z SUNDAY NIGHT)  
ISSUED AT 1155 PM CDT SAT JUN 28 2025  
 
PATCHY FOG IS EXPECTED TO FORM LATE TONIGHT, ESPECIALLY NEAR THE  
I-72 CORRIDOR. INTRODUCED A TEMPO FOR MVFR VISIBILITIES AT KSPI-  
KDEC-KCMI FROM 09-13Z. OTHERWISE A QUIET AVIATION FORECAST WITH  
SCATTERED DIURNAL CU. CALM TO LIGHT/VARIABLE WINDS TONIGHT WILL  
BECOME SOUTH BY LATE MORNING UNDER 10 KT.  
 
25  
 

 
   
ILX WATCHES/WARNINGS/ADVISORIES
 
 
NONE.  

 
 

 
 
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