920  
FXUS63 KILX 292315  
AFDILX  
 
AREA FORECAST DISCUSSION  
NATIONAL WEATHER SERVICE LINCOLN IL  
615 PM CDT SUN MAR 29 2026  
   
KEY MESSAGES  
 
- UNSETTLED WEATHER IS ON TAP FOR MUCH OF THE WEEK. THERE IS A  
60-80% CHANCE OF GREATER THAN 2 INCHES OF RAIN FROM TUESDAY  
THROUGH NEXT SATURDAY.  
 
- THE GREATEST PROBABILITY FOR SEVERE WEATHER WILL FOCUS TUESDAY  
AFTERNOON AND EVENING WHEN A COLD FRONT PUSHES INTO THE  
REGION.  
 
 
   
DISCUSSION  
 
ISSUED AT 241 PM CDT SUN MAR 29 2026  
   
..SEVERE WEATHER RISK ON TUESDAY  
 
AS HAS BEEN NOTED BY THE PAST SEVERAL MODEL RUNS, THE 12Z MAR 29  
SUITE CONTINUES TO SHOW A COLD FRONT DROPPING INTO ILLINOIS LATE  
TUESDAY. WHILE THE EXACT PLACEMENT OF THE BOUNDARY BY PEAK  
HEATING IS STILL IN QUESTION, THE GENERAL CONSENSUS SUGGESTS IT  
WILL BE APPROACHING THE ILLINOIS RIVER VALLEY BY MIDDAY AND I-55  
TOWARD SUNSET. MOISTURE RETURN AHEAD OF THE FRONT WILL BE  
SOMEWHAT LACKING WITH NAM/GFS SHOWING DEWPOINTS MOSTLY IN THE  
MIDDLE TO UPPER 50S...WHICH TRANSLATES TO SBCAPES OF  
1000-1500J/KG. IN ADDITION, DEEP-LAYER SHEAR APPEARS TO BE  
WEAKER THAN IN RECENT SEVERE WEATHER EVENTS AS THE PRIMARY UPPER  
FORCING SLIDES ACROSS THE NORTHERN TIER OF STATES INTO THE  
GREAT LAKES WELL NORTH OF ILLINOIS. NAM GENERALLY INDICATES  
0-6KM BULK SHEAR IN THE 35-45KT RANGE AHEAD OF THE FRONT. WHILE  
THE INSTABILITY/SHEAR PROFILE IS CERTAINLY NOT OFF THE CHARTS,  
THE PRESENCE OF A FORCING MECHANISM COMING INTO THE ENVIRONMENT  
BY PEAK HEATING WILL BE SUFFICIENT TO TRIGGER STRONG TO SEVERE  
THUNDERSTORMS TUESDAY AFTERNOON AND EVENING. AS A RESULT, BOTH  
NCAR AND NSSL MACHINE LEARNING ALGORITHMS INDICATE A GREATER  
THAN 30% CHANCE FOR SEVERE, WHILE COLORADO STATE SHOWS A 15-30%  
CHANCE. AN EARLY ASSESSMENT HIGHLIGHTS THE PRIMARY RISKS AS  
DAMAGING WIND GUSTS AND MARGINALLY SEVERE HAIL.  
   
..UNSETTLED WEATHER THROUGH THE REMAINDER OF THE WEEK  
 
ONE CHANGE THE MOST RECENT MODELS DEPICT IS STALLING THE TUESDAY  
NIGHT FRONTAL BOUNDARY FURTHER NORTH THAN ORIGINALLY THOUGHT.  
INSTEAD OF SINKING INTO THE OHIO RIVER VALLEY ON WEDNESDAY,  
GENERAL CONSENSUS NOW SUGGESTS THE BOUNDARY WILL REMAIN HUNG-UP  
ACROSS CENTRAL ILLINOIS, WHICH WILL KEEP RAIN CHANCES ALIVE  
THROUGH WEDNESDAY. AS A SHORT-WAVE TROUGH EJECTING EASTWARD OUT  
OF THE PLAINS INTERACTS WITH THE BOUNDARY, A WAVE OF LOW  
PRESSURE IS EXPECTED TO DEVELOP AND TRACK NORTHEASTWARD INTO  
INDIANA BY FRIDAY MORNING. THIS WILL BRING ANOTHER WAVE OF  
WIDESPREAD SHOWERS AND A FEW THUNDERSTORMS THURSDAY/THURSDAY  
NIGHT. AFTER A BRIEF LULL IN THE ACTION ON FRIDAY, YET ANOTHER  
WAVE AND ITS ASSOCIATED COLD FRONT WILL ARRIVE LATE FRIDAY NIGHT  
INTO SATURDAY. CONFIDENCE CONTINUES TO GROW THAT BENEFICIAL  
RAINFALL WILL FURTHER ALLEVIATE THE LONG-TERM DROUGHT CONDITIONS  
ACROSS CENTRAL ILLINOIS THIS WEEK. THE LATEST LREF HIGHLIGHTS A  
60-80% CHANCE OF GREATER THAN 2 INCHES OF RAIN ACROSS THE ENTIRE  
AREA...WITH A 30-40% CHANCE OF MORE THAN 3 INCHES SOUTH OF A  
MACOMB TO PONTIAC LINE AND NORTH OF I-70.  
   
..STRONG THUNDERSTORM POTENTIAL NEXT SATURDAY  
 
WHILE IT IS STILL TOO EARLY TO PINPOINT ANY SPECIFIC SEVERE  
WEATHER RISK, THE FINAL SYSTEM OF THE ACTIVE WEEK AHEAD BEARS  
WATCHING FOR NEXT SATURDAY. ALL MODELS AGREE THAT A DIGGING  
UPPER TROUGH WILL PUSH A STRONG COLD FRONT THROUGH CENTRAL  
ILLINOIS SOMETIME FROM FRIDAY NIGHT THROUGH SATURDAY NIGHT. THE  
ECMWF IN PARTICULAR HAS LOOKED RATHER OMINOUS OVER THE PAST FEW  
RUNS, FEATURING A DEEPENING LOW TRACKING FROM IOWA TO MICHIGAN  
AND A TRAILING COLD FRONT PASSING THROUGH CENTRAL ILLINOIS  
SATURDAY AFTERNOON. WHILE MACHINE LEARNING ALGORITHMS DO NOT YET  
HAVE A CLEAR SIGNAL FOR SEVERE, BOTH NCAR AND NSSL INDICATE AT  
LEAST A LOW PROBABILITY. ONCE THE FRONT PASSES, COOLER/DRIER  
CONDITIONS WILL SETTLE BACK INTO THE MIDWEST BY EARLY NEXT WEEK.  
 
 
   
AVIATION /00Z TAFS THROUGH 00Z TUESDAY/  
 
ISSUED AT 615 PM CDT SUN MAR 29 2026  
 
WINDS ALOFT SW 40-45 KTS WILL CAUSE LOW LEVEL WIND SHEAR FROM  
AROUND 06Z-15Z. OTHERWISE, VFR CONDITIONS ARE EXPECTED FOR THE  
UPCOMING 24 HOURS WITH OCCASIONAL SCT-BKN CLOUD COVER AROUND  
5000 FT AGL. WINDS S 10-12 KTS OVERNIGHT, INCREASING TO 14-18  
KTS WITH GUSTS AROUND 25 KTS BY 15Z.  
 
 
   
ILX WATCHES/WARNINGS/ADVISORIES  
 
NONE.  
 
 
 
 
 
KEY MESSAGES...BARNES  
DISCUSSION...BARNES  
AVIATION...37  
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