860  
FXUS63 KILX 050519  
AFDILX  
 
AREA FORECAST DISCUSSION  
NATIONAL WEATHER SERVICE LINCOLN IL  
1219 AM CDT SUN JUL 5 2026  
   
KEY MESSAGES  
 
- SCATTERED STRONG TO SEVERE THUNDERSTORMS WILL TRACK EASTWARD  
ACROSS CENTRAL IL THROUGH EARLY EVENING. THERE IS A SLIGHT  
CHANCE OF SEVERE STORMS FROM I-72 SOUTH, WITH DAMAGING WINDS  
THE PRIMARY SEVERE WEATHER THREAT ALONG HAIL AND LOCALIZED  
TORRENTIAL RAINFALL OF 1-3 INCHES THAT COULD LEAD TO MINOR  
FLOODING ESPECIALLY IN URBAN AREAS.  
 
- A BREAK FROM THE HEAT WAVE ARRIVES EARLY NEXT WEEK. FOLLOWING  
A FINAL ROUND OF SCATTERED SHOWERS AND THUNDERSTORMS ON  
SUNDAY, A COLD FRONT WILL BRING A STRETCH OF DRY AND  
COMFORTABLE WEATHER WITH HIGHS IN THE 80S MONDAY THROUGH  
WEDNESDAY.  
 
 
   
DISCUSSION  
 
ISSUED AT 255 PM CDT SAT JUL 4 2026  
   
HEAT AND HUMIDITY  
 
 
THE HEAT ADVISORY FOR ALL CWA EXCEPT KNOX, STARK AND MARSHALL  
COUNTIES GOES UNTIL 7 PM FOR PEAK HEAT INDICES OF 97-105F. A  
LINE OF THUNDERSTORMS NEAR THE IL RIVER WILL TRACK EASTWARD  
ACROSS CENTRAL AND EASTERN IL INTO EARLY EVENING, AND WILL SEE  
HEAT INDICES DROP AFTER CONVECTION MOVES THROUGH. ALSO SEEING  
SCATTERED CONVECTION OVER HEART OF CWA FROM LINCOLN EASTWARD TO  
DANVILLE AND HEAT INDICES DROPPING IN THESE AREAS TOO WITH THE  
RAIN. WE ENVISION THE HEAT ADVISORY TO BE CANCELLED EARLY OVER  
PORTIONS OF CENTRAL IL DUE TO RAIN COOLED AIR. HEAT INDICES NOT  
AS HOT ON SUNDAY AFTERNOON, PEAKING IN THE UPPER 80S/LOWER 90S  
SO NO HEAT HEADLINES PLANNED ON SUNDAY OVER CENTRAL AND  
SOUTHEAST IL. SO WE APPEAR TO BE IN THE FINAL STRETCH OF A  
WEEK'S LONG HEAT WAVE THAT START OVER CENTRAL/SE IL ON SUNDAY  
AFTERNOON JUNE 28TH.  
   
SEVERE AND HEAVY RAINFALL POTENTIAL THIS WEEKEND  
 
A SEVERE THUNDERSTORM WATCH IS IN EFFECT UNTIL 7 PM TODAY FROM  
STARK, PEORIA, TAZEWELL, LOGAN, MACON, MOULTRIE, COLES AND EDGAR  
COUNTIES NORTHEAST.  
 
AN MCV NEAR THE IA/IL BORDER HAS A SWIRL OF CONVECTION AROUND IT  
INCLUDING BANDS INTO CENTRAL IL NEAR THE IL RIVER, AND FROM  
LINCOLN EASTWARD TO WEST OF DANVILLE. ISOLATED THUNDERSTORMS  
HAD RECENTLY DEVELOPED IN SOUTHEAST IL SOUTH OF I-70. MODERATELY  
UNSTABLE TROPICAL AIRMASS OVER CWA WITH MLCAPES 2000-3500 J/KG  
AND MUCAPES 3000-4000 J/KG. WEAK WIND SHEAR STILL WITH EFFECTIVE  
BULK SHEAR VALUES LESS THAN 25 KTS OVER CENTRAL AND SOUTHERN  
IL. PWATS HAVE INCREASE TO 1.8-2 INCHES AT MID AFTERNOON OVER  
MUCH OF IL SUPPORTING HEAVY RAIN CHANCES. WPC HAS MARGINAL TO  
SLIGHT CHANCE OF EXCESSIVE RAINFALL INTO EARLY EVENING WITH THE  
SLIGHT CHANCE OVER NE CWA. HREF LPMM HAS POCKETS OF 1.5-3 INCHES  
OF RAIN IN LESS THAN 6 HOURS OVER CENTRAL AND NE CWA INTO EARLY  
EVENING. CLINTON JUST HAD 0.6 INCHES OF RAIN IN 20 MINUTES  
WHICH IS 1.8 INCH PER HOUR RATE. NORTHERN IL, NORTH OF CWA HAS A  
FLOOD WATCH IN EFFECT THROUGH 10 PM THIS EVENING.  
 
SPC DAY 1 OUTLOOK HAS SLIGHT RISK OF SEVERE STORMS INTO EARLY  
EVENING FOR MAINLY DAMAGING WINDS (15%) RISK OVER MOST OF CWA  
(THOUGH MAIN THREAT NOW IS ALONG AND EAST OF THE IL RIVER PER  
LATEST RADAR TRENDS). LATEST CAMS GENERALLY SHOW LINE OF  
CONVECTION PUSHING EASTWARD FROM THE IL RIVER TO THE IL/IN  
BORDER EARLY THIS EVENING (BETWEEN 00-01Z/7-8 PM). HAVE JUST  
SLIGHT CHANCES OF SHOWERS/THUNDERSTORMS OVER MOST OF CWA AFTER  
DUSK/9 PM TONIGHT FOR THE 4TH OF JULY FIREWORKS ACTIVITIES,  
WITH 30% POPS SE OF I-70.  
 
AN UPPER LEVEL LEVEL SHORTWAVE TROUGH WILL BEGIN CROSSING IL ON  
SUNDAY, DRAGGING AN ATTENDANT WEAK SURFACE COLD FRONT THROUGH  
CENTRAL ILLINOIS. A LINGERING UNSTABLE AIR MASS AHEAD OF THIS  
FRONT WILL ALLOW ISOLATED TO SCATTERED SHOWERS AND AND  
THUNDERSTORMS TO DEVELOP SUNDAY AFTERNOON/EARLY EVENING  
ESPECIALLY SOUTHEAST OF THE IL RIVER. SPC DAY2 OUTLOOK KEEPS  
MARGINAL RISK OF SEVERE STORMS OF IL ON SUNDAY AFTERNOON/EVENING  
WITH WEAKER INSTABILITY, THOUGH A FEW CELLS COULD BECOME STRONG  
WITH GUSTY WINDS ESPECIALLY IN SOUTHEAST IL. WPC DAY2 ERO HAS A  
MARGINAL RISK OF EXCESSIVE RAINFALL OVER SOUTHEAST IL SUNDAY  
AFTERNOON/EVENING.  
   
NEXT WORK WEEK  
 
ISOLATED SHOWERS AND THUNDERSTORMS ARE POSSIBLE IN EAST CENTRAL  
AND SOUTHEAST IL MONDAY AFTERNOON WITH WEAK UPPER LEVEL LOW/TROF  
OVER THE SOUTHERN GREAT LAKES. OTHERWISE A WELCOME STRETCH OF  
SEASONABLE AND GENERALLY DRY WEATHER IS ANTICIPATED FROM MONDAY  
THROUGH WEDNESDAY WITH WEAK SURFACE HIGH PRESSURE SETTLING INTO  
THE GREAT LAKES REGION AND UPPER LEVEL RIDGING BACK INTO IL  
TUE/WED (500 MB HEIGHTS RISE TO 588-590 DECAMETERS). EXPECT  
DAYTIME HIGHS TO BE IN THE LOW TO MID 80S MONDAY AND MID TO  
UPPER 80S TUE AND WED.  
 
THE MEDIUM TO LONG RANGE FORECAST MODELS SHOW A MORE UNSETTLED  
WEATHER PATTERN RETURNING TO IL DURING THE 2ND HALF OF THE WEEK  
AS AN UPPER LEVEL TROF MOVES INTO THE AREA. A COLD FRONT TO PUSH  
INTO NORTHERN AND POSSIBLY CENTRAL IL AROUND FRIDAY AND STALL  
NEAR THE AREA INTO NEXT WEEKEND. HIS SETUP WILL REINTRODUCE  
DAILY CHANCES FOR SHOWERS AND THUNDERSTORMS FROM THURSDAY INTO  
NEXT WEEKEND. THE CIPS AND CSU-MLP SHOW MARGINAL RISK OF SEVERE  
STORMS OVER NW PARTS OF CWA OVERNIGHT WED NIGHT, OVER MORE OF  
CWA ON THU AND SOUTHERN/SE CWA ON FRIDAY.  
 
THE CLIMATE PREDICTION CENTER (CPC) 8-14 DAY OUTLOOK FOR JULY  
12-18 HAS 33-40% CHANCE OF ABOVE NORMAL TEMPERATURES AND 33-40%  
OF BELOW NORMAL PRECIPITATION OVER IL. CPC'S WEEK 3-4 OUTLOOK  
FOR JULY 18-31 SHOWS EQUAL CHANCES OF ABOVE OR BELOW NORMAL  
TEMPERATURES AND PRECIPITATION.  
 
 
   
AVIATION /06Z TAFS THROUGH 06Z MONDAY/  
 
ISSUED AT 1218 AM CDT SUN JUL 5 2026  
 
A BAGGY AREA OF LOW PRESSURE OVER THE MIDWEST IS RESULTING IN  
VERY LIGHTS WINDS OVERNIGHT, CALM OR VARIABLE AT TIMES THOUGH  
GENERALLY FAVORING A NORTHWESTERLY DIRECTION. PATCHY FOG AND LOW  
STRATUS HAVE ALREADY DEVELOPED AND ANTICIPATE TO INCREASE IN  
COVERAGE OVERNIGHT. SLOW DIURNAL IMPROVEMENT BACK TO MVFR AND  
EVENTUALLY VFR IS EXPECTED SUNDAY MORNING AND AFTERNOON.  
 
 
   
ILX WATCHES/WARNINGS/ADVISORIES  
 
NONE.  
 
 
 
 
 
KEY MESSAGES...07  
DISCUSSION...07  
AVIATION...DEUBELBEISS  
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