740  
FXUS63 KILX 051941  
AFDILX  
 
AREA FORECAST DISCUSSION  
NATIONAL WEATHER SERVICE LINCOLN IL  
241 PM CDT FRI JUN 5 2026  
   
KEY MESSAGES
 
 
- SCATTERED THUNDERSTORMS ARE POSSIBLE LATE TONIGHT THROUGH  
SATURDAY. A FEW STORMS COULD HAVE THE POTENTIAL TO BECOME  
STRONG TO SEVERE, POSING A RISK FOR HEAVY RAIN, LARGE HAIL,  
AND DAMAGING WINDS.  
 
- EXPECT A WARM AND HUMID SATURDAY WITH FEEL-LIKE TEMPERATURES  
CLIMBING INTO THE LOW 90S.  
 
- A STRONGER WARMING TREND ARRIVES TUESDAY THROUGH FRIDAY OF  
NEXT WEEK, PUSHING HEAT INDEX VALUES NEAR 100 DEGREES.  
 

 
   
DISCUSSION
 
 
ISSUED AT 241 PM CDT FRI JUN 5 2026  
 
SURFACE ANALYSIS THIS AFTERNOON SHOWS RIDGING CENTERED OVER THE  
SOUTHEAST US WITH SOUTHWEST RETURN FLOW OVER A GOOD PORTION OF THE  
MIDWEST STATES. A DECAYING LINE OF SHOWERS MOVED THROUGH THE AREA  
EARLIER TODAY WITH SOME ISOLATED ACTIVITY DEVELOPING IN ITS WAKE  
OVER WESTERN AND CENTRAL ILLINOIS THIS AFTERNOON WHERE MODERATELY  
STRONG INSTABILITY HAS DEVELOPED. DESPITE THIS, LITTLE FORCING  
SHOULD LIMIT STORM ORGANIZATION THROUGH EARLY THIS EVENING. AN  
APPROACHING COLD FRONT AND REMNANT OUTFLOW BOUNDARY WILL BE THE  
FOCUS FOR THUNDERSTORM DEVELOPMENT FURTHER WEST OF HERE TONIGHT AS A  
SHORTWAVE TROUGH AND LOW-LEVEL JET PROVIDE LARGE-SCALE ASCENT. THE  
LATEST SUITE OF CAMS SUGGEST THE THUNDERSTORM ACTIVITY WILL SLIDE  
EAST INTO NORTH-CENTRAL ILLINOIS LATE TONIGHT AFTER 1-2 AM (MAINLY  
NEAR/NORTH OF I-74). THE 05.12Z HREF SHOWS 1-2K J/KG OF CAPE IN  
PLACE NORTH OF I-72 OVERNIGHT, THOUGH THE BETTER SHEAR IS DISPLACED  
WELL NORTH OF THE FORECAST AREA. DESPITE THIS, A FEW STORMS MAY  
BECOME STRONG OVERNIGHT INTO SATURDAY MORNING AND POSE A THREAT FOR  
ISOLATED LARGE HAIL AND DAMAGING WINDS. MORE NOTABLY, HEAVY RAIN  
ASSOCIATED WITH THUNDERSTORMS COULD BE THE PRIMARY THREAT WITH  
FORECAST PWATS OF 1.5 TO 2 INCHES AND WARM CLOUD DEPTHS OVER 3K  
METERS - FAVORABLE FOR HIGH RAINFALL RATES. THE HREF'S 24 HOUR  
PRECIPITATION LPMM SHOWS POCKETS OF 1-2" OF RAIN NEAR THE I-74  
CORRIDOR THROUGH SATURDAY MORNING WITH WPC HIGHLIGHTING A MARGINAL  
RISK FOR EXCESSIVE RAINFALL IN THIS SAME AREA.  
 
SURFACE RIDGING BEGINS BUILDING IN FROM THE SOUTHWEST ON SATURDAY,  
TURNING THINGS WARMER AND MORE HUMID FOR THE WEEKEND. LINGERING  
CLOUD COVER MAY SUPPRESS AIR TEMPERATURES SOME ON SATURDAY, BUT ARE  
STILL FORECAST TO CLIMB INTO THE MIDDLE 80S WITH DEWPOINTS  
APPROACHING 70 DEGREES BY AFTERNOON, LEADING TO FEEL-LIKE  
TEMPERATURES IN THE LOW 90S. THE OUTFLOW BOUNDARY FROM OVERNIGHT  
STORMS WILL LINGER OVER CENTRAL ILLINOIS ON SATURDAY WITH CAMS  
SUGGESTING STORMS REGENERATING ALONG IT BY LATE AFTERNOON/EVENING AS  
SBCAPE APPROACHES 2000 J/KG. HOWEVER, WEAK SHEAR AND LARGE SCALE  
SUBSIDENCE SHOULD MINIMIZE STORM ORGANIZATION. HAZARDS WITH ANY  
STORMS THAT DO DEVELOP WILL BE HEAVY RAIN AND GUSTY WINDS AS STORMS  
COLLAPSE.  
 
UPPER RIDGING GETS PUSHED EAST BY SUNDAY AS A CLOSED UPPER LOW  
APPROACHES FROM THE WEST. WIDESPREAD CLOUD COVER AND INCREASING  
PRECIPITATION CHANCES WILL HOLD TEMPERATURES CLOSER TO NORMAL BOTH  
SUNDAY AND MONDAY. UPPER RIDGING WILL BUILD OVER THE PLAINS STATES  
EARLY NEXT WEEK PUSHING THE UPPER LOW OFF TO THE NORTHEAST,  
RESULTING IN A BIG WARM UP IN TEMPERATURES BY THE MIDDLE TO END OF  
NEXT WEEK. AIR TEMPERATURES LOOK TO CLIMB INTO THE UPPER 80S TO LOW  
90S TUESDAY THROUGH FRIDAY, WITH HEAT INDICES APPROACHING 100  
DEGREES. THE LREF (ENS, GEFS, GEPS) SHOWS A 20% CHANCE FOR HEAT  
INDICES TO EXCEED 100 DEGREES WEDNESDAY THROUGH FRIDAY. THIS PAIRED  
WITH LITTLE RELIEF IN TEMPERATURES OVERNIGHT COULD BECOME DANGEROUS,  
ESPECIALLY FOR THOSE WHO HAVE LIMITED OR NO ACCESS TO INDOOR COOLING  
SYSTEMS.  
 

 
   
AVIATION /18Z TAFS THROUGH 18Z SATURDAY/
 
 
ISSUED AT 1238 PM CDT FRI JUN 5 2026  
 
BREEZY SOUTHWEST WINDS WITH GUSTS UP TO 30 KTS WILL CONTINUE THROUGH  
THIS AFTERNOON, LESSENING OVERNIGHT. A DECAYING LINE OF SHOWERS HAS  
RESULTED IN POCKETS OF MVFR CEILINGS, BUT CONDITIONS SHOULD LARGELY  
BE VFR OUTSIDE OF THIS. ADDITIONAL SHOWERS AND STORMS ARE POSSIBLE  
NEAR AND NORTH OF I-74 LATE TONIGHT INTO SATURDAY MORNING, THOUGH  
CONFIDENCE IN EXACT PLACEMENT REMAINS RELATIVELY LOW. PROB30 GROUPS  
REMAIN IN PLACE FOR KPIA, KBMI, AND KCMI LATE TONIGHT, BUT THE  
LATEST GUIDANCE WOULD SUGGEST IT STAYS NORTH OF THE AIRFIELDS.  
WINDS VEER TO THE WEST-SOUTHWEST LATER IN THE PERIOD WITH SPEEDS  
BETWEEN 10-15 KTS.  
 

 
   
ILX WATCHES/WARNINGS/ADVISORIES
 
 
NONE.  
 

 
 

 
 
KEY MESSAGES...NMA  
DISCUSSION...NMA  
AVIATION...NMA  
 
CLICK HERE TO GO TO PREVIOUS BULLETINS.

The Nexlab IL Page Main Text Page