116  
FXUS63 KILX 261527  
AFDILX  
 
AREA FORECAST DISCUSSION...UPDATED  
NATIONAL WEATHER SERVICE LINCOLN IL  
1027 AM CDT SAT JUL 26 2025  
   
KEY MESSAGES  
 
- A FLASH FLOOD WATCH IS IN EFFECT FOR KNOX, STARK, AND MARSHALL  
COUNTIES THROUGH THIS AFTERNOON.  
 
- A HEAT ADVISORY IS IN EFFECT ALONG AND SOUTH OF A JACKSONVILLE  
TO PARIS LINE TODAY. THE OPPRESSIVE HEAT WILL SPREAD BACK  
NORTHWARD ACROSS ALL OF CENTRAL ILLINOIS SUNDAY THROUGH TUESDAY  
AS HEAT INDEX VALUES ONCE AGAIN REACH 105-115.  
 
- A LOW PROBABILITY (5-15% CHANCE) OF SEVERE WEATHER EXISTS NORTH  
OF THE I-70 CORRIDOR TODAY...WITH THE PRIMARY RISKS BEING  
SCATTERED DAMAGING WIND GUSTS AND LARGE HAIL.  
 
 
   
UPDATE  
 
ISSUED AT 1008 AM CDT SAT JUL 26 2025  
 
LATEST RADAR AND SATELLITE ANALYSES REVEAL A DECAYING MCV LIFTING  
ACROSS EXTREME SOUTHEAST IOWA, WITH A PAIR OF OUTFLOW BOUNDARIES  
PUSHING ACROSS CENTRAL ILLINOIS. THESE OUTFLOWS LOOK LIKE THEY  
WILL BECOME POSITIONED VERY NEAR ONE ANOTHER, BOTH ERODING BY  
AFTERNOON SOMEWHERE ALONG A LINE FROM JACKSONVILLE TO GIBSON CITY.  
NORTH OF THIS BOUNDARY, CONDTIONS COULD REMAIN STABLE ENOUGH TO  
STAVE OFF CONVECTIVE RE-DEVELOPMENT THIS AFTERNOON. SOUTH OF IT,  
CAPE/SHEAR PROFILES WILL BE SUPPORTIVE OF STRONG-TO-SEVERE STORMS  
AND SOME URBAN AND SMALL STREAM FLOODING. MANY AREAS ACROSS WEST-  
CENTRAL AND NORTH-CENTRAL ILLINOIS HAVE ALREADY RECEIVED MULTIPLE  
INCHES OF RAINFALL OVER THE PAST 24 HOURS, SOME EVEN SEEING HOURLY  
RAINFALL RATES ECLIPSING 1-2"/HR. GIVEN A SIMILAR AIR MASS IN  
PLACE THIS AFTERNOON NEAR AND SOUTH OF THE RESIDUAL OUTFLOW,  
THINKING WE WILL SEE ADDITIONAL POCKETS OF HEAVY RAINFALL THROUGH  
THE EVENING HOURS.  
 
OTHERWISE, THE DANGEROUS HEAT LOOKS TO BE ON TRACK TO CONTINUE  
THIS AFTERNOON, WITH AREAS WITHIN THE HEAT ADVISORY ALREADY  
DISPLAYING HEAT INDEX VALUES BETWEEN 97-104 F EVEN DESPITE  
INCREASING CLOUD COVER.  
 
LOOK FOR AN EXTENSION OF THE HEAT ADVISORY INTO SUNDAY BY LATER  
THIS AFTERNOON.  
 
MJA  
 
 
   
SHORT TERM  
(TODAY THROUGH SUNDAY)  
ISSUED AT 317 AM CDT SAT JUL 26 2025  
 
CLUSTERS OF THUNDERSTORMS ARE ONGOING ACROSS CENTRAL ILLINOIS  
EARLY THIS MORNING...WITH 0730Z/230AM RADAR SHOWING CELLS  
GENERALLY ALONG A LINCOLN...TO BLOOMINGTON...TO HOOPESTON LINE.  
THIS ACTIVITY WILL TRACK NORTHEASTWARD AND EXIT THE KILX CWA OVER  
THE NEXT 2-3 HOURS. MEANWHILE ADDITIONAL CONVECTION DEVELOPING  
UPSTREAM ACROSS NORTHERN MISSOURI WILL SPILL INTO THE NORTHERN  
COUNTIES, MAINLY IMPACTING LOCATIONS ALONG AND NORTH OF A MACOMB  
TO EL PASO LINE FROM 3AM TO 9AM. HEAVY RAINFALL OCCURRED ACROSS  
PARTS OF THIS AREA EARLIER TODAY WITH MRMS RADAR ESTIMATES SHOWING  
AMOUNTS OF 2-3 INCHES ACROSS SOUTHERN KNOX COUNTY AND AN OBSERVER  
MEASURING 4 INCHES IN THE TOWN OF DELONG SOUTHEAST OF GALESBURG.  
ANY ADDITIONAL RAINFALL FROM THE STORMS EXPECTED THIS MORNING WILL  
OCCUR ON SATURATED SOILS AND COULD POTENTIALLY LEAD TO FLASH  
FLOODING. LATEST RADAR TRENDS SUGGEST THE FIRST CLUSTER OF  
SHOWERS/STORMS WILL ARRIVE ACROSS KNOX AND STARK COUNTIES OVER THE  
NEXT 1-2 HOURS: HOWEVER, ADDITIONAL STORMS FURTHER W/SW MAY TRACK  
A BIT FURTHER NORTH AND STAY JUST NORTH OF THE CWA AFTER SUNRISE.  
NO MATTER THE EXACT TRACK OF THE LATER CONVECTION, THE RISK FOR  
FLASH FLOODING IS GREAT ENOUGH TO CONTINUE THE FLASH FLOOD WATCH  
FOR THE REST OF TODAY.  
 
THE MORNING CONVECTION WILL GRADUALLY DECREASE IN AREAL COVERAGE  
TOWARD MIDDAY...WITH THE EMPHASIS FOR RE-DEVELOPMENT SHIFTING  
FURTHER SOUTH ACROSS THE HEART OF CENTRAL ILLINOIS BY PEAK  
HEATING. WITH HREF MEAN SBCAPES OF 2500-3500J/KG AND 0-6KM SHEAR  
INCREASING TO 25-30KT, THE STAGE WILL BE SET FOR A FEW STRONG TO  
SEVERE CELLS CAPABLE OF PRODUCING DAMAGING WIND GUSTS AND LARGE  
HAIL. AS A RESULT, THE LATEST DAY 1 CONVECTIVE OUTLOOK FROM SPC  
HIGHLIGHTS ALL LOCATIONS NORTH OF THE I-70 CORRIDOR WITH A  
MARGINAL RISK (5-15% CHANCE) FOR SEVERE WEATHER. BASED ON THE  
EXPECTED POSITION OF REMNANT OUTFLOW BOUNDARIES, THE GREATEST  
CHANCE FOR SHOWERS AND STORMS WILL FOCUS FROM I-72 NORTHWARD.  
MEANWHILE FURTHER SOUTH, LOWER RAIN CHANCES AND MORE SUNSHINE WILL  
YIELD ANOTHER HOT AND HUMID SUMMER DAY WITH HEAT INDEX READINGS  
PEAKING AT 100-105 ALONG/SOUTH OF A JACKSONVILLE TO PARIS LINE  
WHERE THE HEAT ADVISORY REMAINS IN EFFECT.  
 
THE UNSETTLED WEATHER WILL CONTINUE INTO SUNDAY AS A PERSISTENT  
FRONTAL BOUNDARY TO THE NORTH AND OLD OUTFLOW BOUNDARIES SERVE AS  
FOCUSING MECHANISMS FOR ADDITIONAL THUNDERSTORMS. THE ATMOSPHERE  
WILL BECOME JUST AS UNSTABLE AS IT WILL BE TODAY: HOWEVER, DEEP-  
LAYER SHEAR WILL BE WEAKER. AS A RESULT, THINK THE STORMS WILL  
REMAIN SUB-SEVERE...WITH THE PRIMARY HAZARD BEING LOCALLY HEAVY  
RAINFALL AND ISOLATED FLASH FLOODING. THANKS TO A SLIGHT UPTICK IN  
TEMPERATURES/DEWPOINTS, HEAT INDEX READINGS WILL CLIMB TO NEAR 105  
ACROSS THE BOARD. IF THESE TRENDS CONTINUE, THE HEAT ADVISORY WILL  
NEED TO EXPANDED BACK NORTHWARD ACROSS ALL OF CENTRAL ILLINOIS.  
 
BARNES  
   
LONG TERM  
(MONDAY THROUGH FRIDAY)  
ISSUED AT 317 AM CDT SAT JUL 26 2025  
 
OPPRESSIVE HEAT AND HUMIDITY WILL PREVAIL BOTH MONDAY AND TUESDAY  
AS UPPER RIDGING BUILDS OVER THE MIDWEST. HEAT INDEX VALUES WILL  
REACH 105-115 BOTH DAYS...WHILE OVERNIGHT VALUES ONLY DROP INTO  
THE UPPER 70S.  
 
AS HAS BEEN NOTED BY THE PAST SEVERAL MODEL RUNS, A PATTERN  
CHANGE WILL TAKE PLACE LATER NEXT WEEK AS ENERGY ROTATING AROUND A  
DEEP UPPER LOW OVER HUDSON BAY SUPPRESSES THE PREVAILING RIDGE  
OVER THE MIDWEST/OHIO RIVER VALLEY. THIS WILL SEND A STRONG COLD  
FRONT THROUGH CENTRAL ILLINOIS ON WEDNESDAY...FOLLOWED BY MUCH  
COOLER AND LESS HUMID CONDITIONS BY THE END OF THE WEEK. THE 00Z  
NBM EVEN SUGGESTS A HIGH PROBABILITY (70-90% CHANCE) THAT HIGH  
TEMPERATURES DROP BELOW 80 DEGREES EVERYWHERE NORTH OF THE I-70  
CORRIDOR BY NEXT FRIDAY.  
 
BARNES  
 
 
   
AVIATION  
(FOR THE 12Z TAFS THROUGH 12Z SUNDAY MORNING)  
ISSUED AT 558 AM CDT SAT JUL 26 2025  
 
A CLUSTER OF CONVECTION EXTENDING FROM KGBG TO KMQB AT 1045Z/545AM  
WILL TRACK NORTHEASTWARD...POTENTIALLY IMPACTING KPIA WITHIN THE  
NEXT 1-2 HOURS. HAVE THEREFORE OPTED TO CARRY THUNDER AT KPIA  
THROUGH 13Z. ADDITIONAL STORMS UPSTREAM ACROSS NORTHERN MISSOURI  
WILL GENERALLY REMAIN NORTH OF KPIA FOR THE REMAINDER OF THE  
MORNING. MODELS HAVE CONSISTENTLY SHOWN ADDITIONAL SCATTERED  
STORMS DEVELOPING ALONG A REMNANT OUTFLOW BOUNDARY LATER THIS  
AFTERNOON/EVENING...ALTHOUGH EXACT AREAL COVERAGE AND TIMING HAVE  
VARIED BETWEEN MODELS AND FROM RUN-TO-RUN. LATEST HRRR SUGGESTS  
THE TIMING MAY BE A BIT LATER THAN ORIGINALLY ANTICIPATED, SO HAVE  
ADJUSTED THE FORECAST ACCORDINGLY. HAVE OPTED TO CARRY A TEMPO  
GROUP FOR THUNDER AT KPIA BETWEEN 20Z AND 00Z AND A PROB30 FOR  
THUNDER AT THE OTHER TERMINALS BETWEEN 23Z AND 03Z. WINDS WILL  
INITIALLY BE LIGHT/VARIABLE, THEN WILL BECOME S/SW AT 8-12KT FROM  
LATE MORNING THROUGH THE AFTERNOON. AS WINDS DECREASE, PATCHY FOG  
DEVELOPMENT WILL BE POSSIBLE LATE TONIGHT. AN EARLY GLANCE AT THE  
CAMS SHOWS BOTH THE HRRR AND GFSLAMP FORECASTING REDUCED VISBYS  
ALONG/NORTH OF I-72.  
 
BARNES  
 
 
   
ILX WATCHES/WARNINGS/ADVISORIES  
 
FLOOD WATCH UNTIL 7 PM CDT THIS EVENING FOR ILZ027-028-030.  
 
HEAT ADVISORY UNTIL 7 PM CDT THIS EVENING FOR ILZ049>057-061>063-  
066>068-071>073.  
 
 
 
 
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