360  
FXUS63 KILX 171103  
AFDILX  
 
AREA FORECAST DISCUSSION  
NATIONAL WEATHER SERVICE LINCOLN IL  
603 AM CDT FRI APR 17 2026  
   
KEY MESSAGES
 
 
- THERE IS AN ENHANCED RISK (LEVEL 3 OF 5) OF SEVERE  
THUNDERSTORMS FROM CHAMPAIGN TO PANA WEST FOR LATE THIS  
AFTERNOON AND EVENING. A SLIGHT RISK (LEVEL 2 OF 5) EXTENDS AS  
FAR SOUTHEAST AS A TERRE HAUTE TO OLNEY LINE. DAMAGING WINDS,  
LARGE HAIL AND TORNADOES ARE ALL POSSIBLE.  
 
- LOW TEMPERATURES IN THE 30S COULD LEAD TO FROST DEVELOPING  
BOTH OVERNIGHT SATURDAY NIGHT AND SUNDAY NIGHT. THIS COULD  
HARM ANY SENSITIVE EARLY SEASON VEGETATION, AS THE GROWING  
SEASON HAS STARTED ACROSS ILLINOIS.  
 

 
   
DISCUSSION
 
 
ISSUED AT 400 AM CDT FRI APR 17 2026  
 
AREAS OF DENSE FOG OVER NORTHEAST IL FROM MORRIS TO KANKAKEE  
NORTHEAST INTO LAKE MICHIGAN WILL STAY NORTHEAST OF CENTRAL IL  
EARLY THIS MORNING AS BREEZY SOUTH WINDS DEVELOP TODAY WITH  
PASSAGE OF A WARM FRONT/TROF DURING THIS MORNING. SOUTHERLY WIND  
GUSTS OF 25-35 MPH LIKELY OVER CENTRAL IL THIS AFTERNOON. THIS  
WILL BRING ANOTHER UNSEASONABLY WARM AND HUMID SUMMERLIKE DAY  
WITH HIGHS IN THE LOW TO MID 80S AND DEWPOINTS IN THE LOW TO  
MID 60S.  
 
LATEST CAMS SHOW ISOLATED SHOWERS/THUNDERSTORMS DEVELOPING OVER  
PARTS OF EAST CENTRAL AND SOUTHEAST IL BY MIDDAY/EARLY  
AFTERNOON DUE TO WAA. THE MAIN WEATHER STORY WILL BE STRONG 994  
MB LOW PRESSURE OVER SOUTH CENTRAL NEBRASKA THAT TRACKS  
NORTHEAST OF GREEN BAY WI BY 06Z/1 AM TONIGHT AND PULLS A STRONG  
COLD FRONT EASTWARD OVER THE IL RIVER VALLEY. MODERATE TO STRONG  
INSTABILITY DEVELOPS AHEAD OF THIS COLD FRONT OVER EASTERN/SE  
IOWA AND NORTHERN MO DURING EARLY/MID AFTERNOON WITH SBCAPES  
ABOVE 3000 J/KG WHILE 2-3K J/KG SB CAPES OVER CENTRAL AND  
WESTERN CWA THIS AFTERNOON WEST OF I-57. WIND SHEAR VALUES PEAK  
FORM 30-40 KTS OVER CENTRAL IL LATE AFTERNOON/EVENING. INITIALLY  
SUPERCELLS WILL LIKELY DEVELOP DURING THIS AFTERNOON OVER  
EASTERN IA, NORTHERN MO INTO NW IL WITH A FEW SUPERCELLS  
POSSIBLE OVER THE IL RIVER VALLEY DURING MID/LATE AFTERNOON.  
THESE COULD CONTAIN LARGE HAIL AND POSSIBLE TORNADOES WITH  
STRONGER TORNADOES EF2 OR STRONGER WEST OF THE IL RIVER, WITH  
EF3 OR STRONGER NW OF GALESBURG MAINLY DURING LATE  
AFTERNOON/EARLY EVENING. EXPECT A SQUALL LINE TO EVENTUALLY  
DEVELOP AND TRACK EASTWARD ACROSS CENTRAL IL DURING THIS EVENING  
WITH DAMAGING WINDS BECOMING THE PRIMARY THREAT AND COULD BE  
WINDS OVER 75 MPH IN THE ENHANCED RISK AREA FROM CHAMPAIGN TO  
PANA WEST. THE LINE OF STORMS IS FORECAST TO WILL IMPACT EAST  
CENTRAL/SE IL LATER THIS EVENING AND EARLY OVERNIGHT AND COULD  
STILL SEE SEVERE STORMS. WPC DAY1 OUTLOOK HAS A SLIGHT CHANCE OF  
EXCESSIVE RAINFALL OVER CENTRAL AND NW IL LATE THIS AFTERNOON  
INTO TONIGHT, WITH MARGINAL RISK OF EXCESSIVE RAINFALL IN  
SOUTHEAST IL TONIGHT. BETWEEN THREE QUARTER AND 1 INCH OF RAIN  
EXPECTED OVERALL WITH SOME AREAS SEEING 1-1.5 INCHES ESPECIALLY  
OVER THE IL RIVER VALLEY.  
 
RAIN SHOWERS AND ISOLATED THUNDERSTORMS IN EAST CENTRAL AND  
SOUTHEAST IL SAT MORNING, TO DIMINISH BY MIDDAY. BREEZY NW  
WINDS BEHIND THE COLD FRONT ON SATURDAY TO BRING IN MUCH COOLER  
AIR AND WILL LIKELY SEE TEMPERATURES SLIPPING INTO 30S OVERNIGHT  
SAT NIGHT WITH FROST LIKELY OVER CENTRAL IL BY DAWN SUNDAY  
ESPECIALLY NORTH OF I-72. UPPER LEVEL TROF DIGGING INTO IL SAT  
NIGHT WILL CONTINUE TO INFLUENCE IL ON SUNDAY WITH COOL  
CONDITIONS. LOWS AGAIN IN THE 30S SUNDAY NIGHT WITH FROST  
LIKELY OVERNIGHT SUNDAY NIGHT OVER CENTRAL AND NE CWA AS  
CANADIAN HIGH PRESSURE SETTLES IN WITH LIGHTER WINDS.  
 
WARMUP IN STORE FROM MONDAY THROUGH MID WEEK AS UPPER LEVEL  
TROF SHIFTS INTO NEW ENGLAND AND MID ATLANTIC STATES ON MONDAY,  
AND UPPER LEVEL RIDGE BUILDING INTO IL BY THU. HIGHS IN THE LOW  
TO MID 60S MON CLIMB INTO THE MID TO UPPER 70S TUE AND UPPER  
70S/LOWER 80S WED/THU. PRECIPITATION CHANCES LOOK LOW DURING  
EARLY TO MID WEEK, WITH NEXT STORMS SYSTEM FORECAST TO PUSH INTO  
THE MIDWEST AROUND NEXT FRI/FRI NIGHT WITH BETTER CHANCE OF  
SHOWERS AND THUNDERSTORMS.  
 
THE CLIMATE PREDICTION 6-10 DAY OUTLOOK FOR APR 22-26 HAS A  
45-55% CHANCE OF ABOVE NORMAL TEMPERATURES OVER CENTRAL/SE IL  
AND A 40-45% CHANCE OF ABOVE NORMAL PRECIPITATION.  
 

 
   
AVIATION /12Z TAFS THROUGH 12Z SATURDAY/
 
 
ISSUED AT 558 AM CDT FRI APR 17 2026  
 
PATCHY FOG AT CMI EARLY THIS MORNING WITH VSBYS AS LOW AS 3/4SM  
TO 2SM SINCE 0930Z IS STARTED TO LIFT ABOVE 4 MILES WITH  
INCREASING HIGH CLOUDS AND SE WINDS UP TO 7 KTS. HAVE TEMPO  
PERIOD OF MVFR VSBY WITH LIGHT FOG AT CMI UNTIL 13Z. OTHERWISE  
SOUTH TO SE WINDS UNDER 10 KTS EARLY THIS MORNING TO VEER SOUTH  
AND INCREASE TO 16-22 KTS WITH GUSTS 25-32 KTS BY LATE MORNING  
AND CONTINUE THROUGH THE AFTERNOON. SCATTERED CUMULUS CLOUDS  
WITH BASES 3-5K FT TO APPEAR DURING THIS MORNING WITH BROKEN  
HIGH CLOUDS. THE 09Z HRRR MODEL KEEPS ISOLATED SHOWERS WEST OF  
PIA AND SPI AND SOUTH OF CMI THROUGH EARLY AFTERNOON. AN  
APPROACHING STRONG COLD TO LIKELY BRING A SQUALL LINE EAST TO  
PIA AROUND 01Z, TO BMI AND SPI BY 03Z AND DEC AND CMI BETWEEN  
04-05Z. HAVE A 2 HOUR PERIOD OF WNW WINDS 35G45 KTS WITH +1TSRA  
AND MVFR CEILINGS. SHOWERS DIMINISH BETWEEN 09Z-12Z BEHIND COLD  
FRONT OVERNIGHT WITH MVFR CEILINGS LINGERING. WEST TO NW WINDS  
REMAIN GUSTY AT 20-25 KTS OVERNIGHT INTO SAT MORNING.  
 

 
   
ILX WATCHES/WARNINGS/ADVISORIES
 
 
NONE.  
 

 
 

 
 
KEY MESSAGES...07  
DISCUSSION...07  
AVIATION...07/DEUBELBEISS  
 
CLICK HERE TO GO TO PREVIOUS BULLETINS.

The Nexlab IL Page Main Text Page