800  
FXUS63 KILX 252312  
AFDILX  
 
AREA FORECAST DISCUSSION...UPDATED AVIATION  
NATIONAL WEATHER SERVICE LINCOLN IL  
612 PM CDT FRI APR 25 2025  
   
KEY MESSAGES
 
 
- THE NEXT SIGNIFICANT CHANCE FOR THUNDERSTORMS WILL ARRIVE EARLY  
NEXT WEEK AS A COLD FRONT APPROACHES FROM THE WEST. THERE IS A  
15% CHANCE FOR SEVERE WEATHER NORTHWEST OF A LITCHFIELD TO  
HOOPESTON LINE MONDAY NIGHT...AND EVERYWHERE EAST OF THE  
ILLINOIS RIVER DURING THE DAY TUESDAY.  
 
- IN ADDITION TO THE STORM CHANCES, IT WILL BECOME WINDY AND VERY  
WARM AHEAD OF THE FRONT ON MONDAY...WITH THE LATEST GUIDANCE  
SUGGESTING A HIGH PROBABILITY (60-90% CHANCE) FOR WIND GUSTS  
GREATER THAN 30MPH.  
 

 
   
DISCUSSION
 
 
ISSUED AT 228 PM CDT FRI APR 25 2025  
   
..SCATTERED CONVECTION THIS AFTERNOON/EVENING
 
 
18Z/1PM SURFACE ANALYSIS SHOWS A SLOW-MOVING COLD FRONT EXTENDING  
FROM SOUTHERN MICHIGAN SOUTHWESTWARD INTO MISSOURI. WHILE THE BULK  
OF THE PRECIP THAT TRACKED ACROSS THE AREA THIS MORNING HAS PUSHED  
EAST OF THE I-57 CORRIDOR AND DECREASED IN AREAL COVERAGE, NEW  
CONVECTION IS BEGINNING TO FORM ALONG THE FRONT FROM JUST SOUTH OF  
LEWISTOWN TO NEAR JACKSONVILLE. GIVEN PARTIAL SUNSHINE HEATING  
TEMPERATURES INTO THE LOWER TO MIDDLE 70S AND SURFACE DEWPOINTS  
HOVERING IN THE 60S, SPC MESOANALYSIS INDICATES SBCAPES HAVE RISEN  
INTO THE 1000-1500J/KG RANGE. WEAK CONVERGENCE ALONG THE BOUNDARY  
AND DEEP LAYER SHEAR OF LESS THAN 30KT WILL BE MITIGATING FACTORS  
FOR VIGOROUS CONVECTION: HOWEVER, THINK THIS BAND OF SCATTERED  
SHOWERS AND THUNDERSTORMS WILL CONTINUE TO WORK ITS WAY EASTWARD  
ACROSS THE AREA...GENERALLY IMPACTING LOCATIONS ALONG/SOUTH OF A  
LEWISTOWN...TO BLOOMINGTON...TO HOOPESTON LINE BETWEEN NOW AND  
ABOUT 8-9PM. AFTER THAT, THE SHOWERS WILL PUSH INTO INDIANA AND  
DISSIPATE BY LATE EVENING.  
   
..WINDY AND MUCH WARMER CONDITIONS ON MONDAY
 
 
AS HIGH PRESSURE PUSHES EASTWARD INTO THE OHIO RIVER VALLEY,  
SOUTHEASTERLY RETURN FLOW WILL COMMENCE ON SUNDAY. SOME CAMS  
SUGGEST A FEW WAA SHOWERS WILL BE POSSIBLE ACROSS THE W/SW CWA:  
HOWEVER, THESE WILL BE FIGHTING A DRY LOW-LEVEL AIRMASS AND WILL  
NOT AMOUNT TO MUCH EVEN IF THEY DO OCCUR. AS THE HIGH SHIFTS  
FURTHER EAST AND A COLD FRONT APPROACHES FROM THE WEST, A  
TIGHTENING PRESSURE GRADIENT WILL LEAD TO INCREASING WINDS ON  
MONDAY. THE 00Z APR 25 LREF IS SHOWING A HIGH PROBABILITY (60-90%  
CHANCE) FOR SOUTHERLY WIND GUSTS EXCEEDING 30MPH EVERYWHERE NORTH  
OF THE I-70 CORRIDOR BY MONDAY AFTERNOON. BOTH THE LREF AND NBM  
INDICATE A STRONG SIGNAL FOR WIND GUSTS OVER 30MPH ON MONDAY AND  
IN THE 25-30MPH RANGE INTO TUESDAY AS WELL. WITH SUNSHINE AND  
STRONG SOUTHERLY WINDS, THE 570DM 1000-500MB THICKNESS LINE IS  
PROGGED TO SURGE NORTHWARD INTO THE AREA...SUPPORTING MONDAY  
AFTERNOON HIGHS IN THE LOWER TO MIDDLE 80S.  
   
..SEVERE WEATHER RISK MONDAY NIGHT
 
 
THE APPROACHING COLD FRONT WILL INTERACT WITH A HIGHLY UNSTABLE  
(GFS SBCAPES 2000-3000J/KG) AND STRONGLY SHEARED (GFS 0-6KM BULK  
SHEAR GREATER THAN 50KT) ENVIRONMENT TO TRIGGER A LINE OF SEVERE  
CONVECTION ACROSS WESTERN WISCONSIN INTO IOWA BY LATE MONDAY  
AFTERNOON/EVENING. THIS CONVECTION WILL THEN TRANSLATE EASTWARD  
INTO THE ILLINOIS RIVER VALLEY AFTER DARK AND WILL LIKELY CONTINUE  
EASTWARD TO THE I-57 CORRIDOR TOWARD DAWN TUESDAY. WHILE THE  
STORMS WILL BE UNDERGOING SOME DEGREE OF DIURNAL WEAKENING, AMPLE  
WIND ENERGY IN THE ENVIRONMENT WILL KEEP THE RISK OF AT LEAST  
SCATTERED SEVERE WIND GUSTS ALIVE ACROSS A GOOD PORTION OF THE  
KILX CWA. THE LATEST SPC OUTLOOK HIGHLIGHTS LOCATIONS ALONG/WEST  
OF A LITCHFIELD TO HOOPESTON LINE...AND THIS STILL LOOKS GOOD  
BASED ON THE LATEST DATA.  
   
..SEVERE WEATHER RISK TUESDAY AFTERNOON/EVENING
 
 
THE BIG QUESTION FOR TUESDAY WILL BE EXACTLY WHERE CONVECTION WILL  
RE-DEVELOP AHEAD OF THE COLD FRONT/OUTFLOW BOUNDARY DURING THE  
AFTERNOON. THE GFS CONTINUES TO SUGGEST INITIATION WILL BE ACROSS  
THE HEART OF CENTRAL ILLINOIS: HOWEVER, THE 12Z ECMWF IS SHOWING  
THINGS SETTING UP A BIT FURTHER SOUTH...PERHAPS ALONG THE I-70  
CORRIDOR. WILL NEED TO KEEP A CLOSE EYE ON WHERE THE STORMS  
EVENTUALLY FIRE, BECAUSE DEEP-LAYER KINEMATICS ASSOCIATED WITH THE  
RIGHT ENTRANCE REGION OF A 110-120KT 300MB JET STREAK ACROSS THE  
GREAT LAKES WILL BE FAVORABLE FOR SIGNIFICANT SYNOPTIC LIFT. IN  
ADDITION, STRONG CONVERGENCE ALONG THE COLD FRONT WILL SUPPORT  
VIGOROUS UPDRAFTS AND THE SUBSEQUENT RISK FOR LARGE HAIL AND  
DAMAGING WIND GUSTS FROM MID-AFTERNOON INTO THE EVENING.  
 
BARNES  
 

 
   
AVIATION
 
(FOR THE 00Z TAFS THROUGH 00Z SATURDAY EVENING)  
ISSUED AT 612 PM CDT FRI APR 25 2025  
 
MVFR CIGS ARE EXPECTED TO SPREAD OVER THE CENTRAL IL TERMINALS  
FROM THE NORTHWEST THIS EVENING, LINGERING INTO SATURDAY MORNING.  
ALTHOUGH TIMING CONTINUES TO HAVE UNCERTAINTY, START OF MVFR LOOKS  
TO BE ANYWHERE FROM BEFORE 00Z AT KBMI TO 03Z AT KDEC, AND END  
LOOKS TO BE AROUND 15Z-17Z. WINDS N 10-15 KTS WITH GUSTS AROUND 20  
KTS THIS EVENING, DECREASING TO 10-12 KTS AND SHIFTING TO NNE  
OVERNIGHT.  
 
37  
 

 
   
ILX WATCHES/WARNINGS/ADVISORIES
 
 
NONE.  

 
 

 
 
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