636  
FXUS63 KILX 271600  
AFDILX  
 
AREA FORECAST DISCUSSION  
NATIONAL WEATHER SERVICE LINCOLN IL  
1100 AM CDT WED MAY 27 2026  
   
KEY MESSAGES  
 
- SHOWERS AND A FEW THUNDERSTORMS WILL PERSIST SOUTH OF I-72  
TODAY...WITH A NARROW CORRIDOR FROM PARIS TO SHELBYVILLE  
POTENTIALLY PICKING UP GREATER THAN 1 INCH OF RAINFALL.  
 
- AIR QUALITY WILL BECOME UNHEALTHY FOR SENSITIVE GROUPS ACROSS  
PORTIONS OF CENTRAL ILLINOIS TODAY DUE TO HIGH OZONE  
CONCENTRATIONS.  
 
- NO MAJOR STORM SYSTEMS ARE EXPECTED TO IMPACT THE REGION OVER  
THE NEXT WEEK. AS A RESULT, THE SEVERE WEATHER RISK WILL  
REMAIN VERY LOW (LESS THAN A 5% CHANCE) THROUGH NEXT TUESDAY.  
 
 
   
UPDATE  
 
ISSUED AT 1100 AM CDT WED MAY 27 2026  
 
SOME MINOR ADJUSTMENTS TO CHANCES OF SHOWERS AND ISOLATED  
THUNDERSTORMS OVER SE CWA INTO THIS AFTERNOON. REST OF FORECAST  
LOOKS ON TRACK REST OF TODAY. SHOWERS HAVE BEEN DIMINISHING FROM  
I-72 SOUTH PAST FEW HOURS, WITH A FEW LIGHT SHOWERS REMAINING NEAR  
I-72 AT LATE MORNING. LATEST CAMS LIKE HRRR SHOW SOME  
REDEVELOPMENT OF CONVECTION IN SOUTHEAST IL DURING MIDDAY AND  
PROGRESSING SE DURING THE AFTERNOON, EXITING FAR SE CWA BY  
23-00Z (6-7 PM). PW VALUES ARE 1.5-1.6 INCHES IN SOUTHEAST IL  
AND COULD SEE ISOLATED BRIEF HEAVY RAINS IN SOUTHEAST IL DURING  
THIS AFTERNOON. SPC DAY1 KEEPS MARGINAL RISK OF SEVERE STORMS  
THIS AFTERNOON/EARLY EVENING EAST OF IL OVER SE INDIANA,  
SOUTHERN OHIO AND NORTHEAST KY WHERE 5-14% RISK OF DAMAGING  
WINDS ARE. MORE SUNSHINE OVER THE NW HALF OF CWA WITH HIGHS IN  
THE MID TO UPPER 80S (ALREADY LOWER 80S FROM I-55 NW AT 11 AM).  
MOSTLY CLOUDY TO OVERCAST SKIES ALONG AND SOUTH OF I-72 TO HAVE  
DECREASING CLOUDS FROM NW TO SE DURING THE AFTERNOON WITH HIGHS  
IN THE UPPER 70S/LOWER 80S.  
 
 
   
DISCUSSION  
 
ISSUED AT 338 AM CDT WED MAY 27 2026  
 
*** SHOWERS SOUTH OF I-72 TODAY ***  
 
08Z/3AM RADAR IMAGERY SHOWS A BAND OF SHOWERS AND THUNDERSTORMS  
EXTENDING FROM NEAR PARIS TO SHELBYVILLE. THIS ACTIVITY HAS BEEN  
LIFTING SLOWLY NORTHWARD OVER THE PAST COUPLE OF HOURS, BUT IS  
LOSING SOME OF ITS MOMENTUM AS THE SHORT-WAVE TROUGH THAT  
TRIGGERED IT PIVOTS NORTHEASTWARD INTO INDIANA. IN ADDITION,  
THE SHOWERS WILL BE ENCOUNTERING A CONSIDERABLY DRIER/MORE  
SUBSIDENT AIRMASS NORTH OF THE I-72 CORRIDOR WHERE CURRENT  
DEWPOINTS ARE ONLY IN THE 50S. CAMS SEEM TO HAVE A GOOD HANDLE  
ON THE BAND AND SUGGEST IT WILL EVENTUALLY STALL AND BEGIN TO  
DISSIPATE NEAR OR JUST SOUTH OF A DANVILLE TO DECATUR LINE BY  
DAYBREAK. AFTER A LULL IN PRECIP CHANCES BY MID TO LATE MORNING,  
ADDITIONAL SHOWERS AND STORMS WILL DEVELOP ACROSS THE SAME AREA  
THIS AFTERNOON BEFORE GRADUALLY DROPPING SOUTHEASTWARD AND  
EXITING INTO THE OHIO RIVER VALLEY BY EARLY EVENING. WHILE NOT  
ALL LOCATIONS ACROSS EAST-CENTRAL AND SOUTHEAST ILLINOIS WILL  
SEE RAINFALL, A FAVORED CORRIDOR FROM PARIS TO SHELBYVILLE MAY  
SEE AMOUNTS OVER 1 INCH. MEANWHILE NORTH OF I-72, CONDITIONS  
WILL REMAIN DRY. HIGH TEMPERATURES WILL RANGE FROM THE UPPER 70S  
NEAR I-70...TO THE UPPER 80S ALONG/NORTHWEST OF THE ILLINOIS  
RIVER.  
 
*** POOR AIR QUALITY TODAY ***  
 
ELEVATED OZONE LEVELS IN THE CHICAGO AREA WILL GRADUALLY ADVECT  
INTO CENTRAL ILLINOIS TODAY DUE TO WEAK NORTHEASTERLY FLOW  
AROUND HIGH PRESSURE OVER THE UPPER MIDWEST. THE ILLINOIS  
ENVIRONMENTAL PROTECTION AGENCY (EPA) INDICATES AIR QUALITY WILL  
BECOME UNHEALTHY FOR SENSITIVE GROUPS ALONG/NORTH OF I-74. A  
WEAK COLD FRONT CURRENTLY OVER WISCONSIN WILL DROP SOUTHWARD  
THROUGH THE REGION TONIGHT, RESULTING IN INCREASING NORTHEASTERLY  
WINDS WHICH SHOULD HELP DISPERSE THE OZONE AND IMPROVE AIR  
QUALITY BY THURSDAY.  
 
*** PROLONGED STRETCH OF QUIET WEATHER ***  
 
AN OMEGA BLOCK WILL DEVELOP ACROSS THE CONUS...FEATURING DEEP  
UPPER LOWS ALONG THE WEST COAST AND OVER NEW ENGLAND AND A  
PERSISTENT RIDGE SANDWICHED BETWEEN THEM OVER THE MIDWEST. THIS  
WILL ENSURE ANY APPROACHING SHORT-WAVES WILL BE SHUNTED S/SW OF  
CENTRAL ILLINOIS THROUGH AT LEAST EARLY NEXT WEEK. AS A RESULT,  
AM EXPECTING DRY CONDITIONS THURSDAY THROUGH NEXT NEXT TUESDAY  
WITH SEASONABLE HIGH TEMPERATURES RANGING FROM THE UPPER 70S TO  
THE MIDDLE 80S.  
 
 
   
AVIATION /12Z TAFS THROUGH 12Z THURSDAY/  
 
ISSUED AT 553 AM CDT WED MAY 27 2026  
 
1030Z/530AM RADAR IMAGERY SHOWS A BAND OF SHOWERS ALONG/SOUTH OF  
A KCMI TO KDEC LINE. THE BAND HAS BECOME NEARLY STATIONARY AND  
IS EXPECTED TO GRADUALLY DISSIPATE OVER THE NEXT FEW HOURS.  
BASED ON LATEST OBS AND HRRR/RAP GUIDANCE, HAVE CARRIED  
PREDOMINANT SHOWERS AT BOTH KCMI AND KDEC THROUGH 15Z. THE BIG  
QUESTION WILL BE HOW LOW CEILINGS WILL DROP AT THOSE SITES AS  
THE RAIN FALLS. KCMI HAS OCCASIONALLY DIPPED TO MVFR: HOWEVER,  
KDEC AND KTAZ HAVE REMAINED VFR. HRRR CEILING FORECAST KEEPS THE  
LOW CLOUDS LOCKED IN PLACE, THEN GRADUALLY SHIFTS THEM E/SE BY  
MID-MORNING. AS A RESULT, HAVE OPTED TO GO WITH AN MVFR OVERCAST  
AT KCMI THROUGH 15Z, BUT KEEP KDEC LOW VFR. ONCE THE LOW  
CLOUDS/SHOWERS DEPART, SKIES WILL GRADUALLY CLEAR FROM NORTHWEST  
TO SOUTHEAST ACROSS THE AREA THIS AFTERNOON. WINDS WILL REMAIN  
LIGHT FROM THE NE AT 5-10KT THROUGH THE ENTIRE 12Z TAF PERIOD,  
BUT MAY INCREASE AND BECOME GUSTY AT THE I-74 TERMINALS AFTER  
09Z AS A COLD FRONT DROPS SOUTHWARD THROUGH THE REGION LATE  
TONIGHT.  
 
 
   
ILX WATCHES/WARNINGS/ADVISORIES  
 
NONE.  
 
 
 
 
 
KEY MESSAGES...BARNES  
UPDATE...07  
DISCUSSION...BARNES  
AVIATION...BARNES/SHIMON  
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