965  
FXUS63 KILX 280447  
AFDILX  
 
AREA FORECAST DISCUSSION  
NATIONAL WEATHER SERVICE LINCOLN IL  
1147 PM CDT SUN SEP 27 2026  
   
KEY MESSAGES
 
 
- QUIET AND TRANQUIL WEATHER CONTINUES ACROSS CENTRAL AND  
SOUTHEAST ILLINOIS THROUGH TUESDAY NIGHT, WITH SEASONABLE HIGH  
TEMPERATURES IN THE MID TO UPPER 70S MONDAY AND UPPER 70S AND  
LOWER 80S TUESDAY. PATCHY SHALLOW GROUND FOG POSSIBLE LATE  
TONIGHT AND EARLY MONDAY MORNING NORTHEAST OF I-74 AND NEAR  
THE INDIANA BORDER.  
 
- WIDESPREAD SHOWERS AND A FEW THUNDERSTORMS ARE EXPECTED  
THURSDAY THROUGH FRIDAY OVER CENTRAL AND SOUTHEAST IL. THE  
EXACT LOCATION OF THE HEAVIEST RAINFALL AND ACCUMULATIONS  
REMAIN HIGHLY UNCERTAIN, AND CURRENT NBM FORECAST AMOUNTS  
HAVE COME DOWN TO BETWEEN 1.5 AND 2 INCHES.  
 

 
   
DISCUSSION
 
 
ISSUED AT 230 PM CDT SUN SEP 27 2026  
 
A BLOCKY UPPER LEVEL PATTERN CONTINUES ACROSS THE COUNTRY NEXT  
FEW DAYS WITH STRONG CUTOFF LOW/TROFS OVER THE MID ATLANTIC  
COAST AND WEST COAST EARLY THIS WEEK AND UPPER LEVEL RIDGE IN  
BETWEEN OVER THE NATIONS HEARTLAND. QUIET/NICE EARLY FALL  
WEATHER WILL LIKELY CONTINUE ACROSS CENTRAL/SE IL THROUGH AT  
LEAST TUESDAY NIGHT AND MAY EVEN EXTEND INTO WEDNESDAY AS THE  
WESTERN UPPER LEVEL TROF IS SLOWER TO SHIFT EASTWARD INTO THE  
CENTRAL ROCKIES/CENTRAL HIGH PLAINS ON WED. MORE ACTIVE PATTERN  
EVOLVES OVER THE REGION WED NIGHT INTO FRIDAY AS SYSTEM IN  
WESTERN STATES MOVES INTO THE MIDWEST WITH A FRONTAL BOUNDARY  
ALONG WITH REMNANTS OF POLO AFFECTING THE AREA LATE THIS WORK  
WEEK.  
 
MID LEVEL CONVERGENCE DRIVEN BAND OF ISOLATED TO SCATTERED  
SHOWERS OVER EASTERN IOWA CENTRAL/EASTERN MO, AR AND WEST  
CENTRAL AND FAR SW IL NEAR MS RIVER VALLEY FROM NEAR  
JACKSONVILLE AND SOUTH AND SW. JACKSONVILLE AIRPORT PICKED UP  
0.13 INCH RAIN THIS MORNING. LATEST CAMS CONTINUE TO DIMINISH  
THESE LIGHT SHOWERS NEXT FEW HOURS OVER AREAS FROM JACKSONVILLE  
SW WITH DRY CONDITIONS EXPECTED OVER AREA BY SUNSET. SOME OF THE  
CAM MEMBERS LIKE HRRR, RAP AND NAM3KM SHOW PATCHY FOG (POSSIBLY  
DENSE) DEVELOPING FROM I-74 NORTHEAST AND NEAR THE IN BORDER  
DURING OVERNIGHT INTO EARLY MONDAY MORNING. LOWS OVERNIGHT IN  
THE UPPER 40S/LOWER 50S, COOLEST EAST OF I-55 WHERE LESS CLOUD  
COVER.  
 
UPPER LEVEL RIDGE BUILDS INTO IL THROUGH TUE WITH TEMPERATURES  
GRADUALLY WARMING UP INTO MID TO UPPER 70S MONDAY AND MOSTLY  
LOWER 80S TUE (UPPER 70S OVER KNOX AND STARK COUNTIES). LOWS IN  
THE LOW TO MID 50S MONDAY NIGHT, COOLEST IN EAST CENTRAL IL. EVEN  
WARMER ON WED WITH SOUTHERLY FLOW WITH HIGHS RANGING FROM UPPER  
70S BY GALESBURG TO MID TO UPPER 80S IN SOUTHEAST IL. WE HAVE  
20-40% CHANCE OF SHOWERS FROM QUINCY TO BLOOMINGTON NORTH/NW ON  
WED WITH ISOLATED THUNDERSTORMS FROM GALESBURG NW. HIGHS THU  
STILL IN MID 80S IN SOUTHEAST IL WHILE LOW TO MID 70S FROM IL  
RIVER NW.  
 
THE STRONG UPPER LEVEL TROF NEAR THE WEST COAST TO SHIFT  
EASTWARD INTO THE CENTRAL ROCKIES AND CENTRAL HIGH PLAINS BY WED  
WHILE PICKING UP REMNANTS OF HURRICANE POLO WITH SHOWERS AND A  
FEW THUNDERSTORMS BECOMING MORE LIKELY OVERNIGHT WED NIGHT OVER  
THE IL RIVER VALLEY AND OVER REST OF CWA ON THU, THOUGH  
SOUTHEAST IL MAY NOT SEE LIKELY POPS UNTIL THU NIGHT/FRIDAY.  
HURRICANE POLO WITH 125 MPH WINDS FORECAST BY NHC TO TRACK NE  
INTO SOUTHERN BAJA OF MEXICO LATE MONDAY AFTERNOON AND WEAKEN AS  
IT MOVES ACROSS THE BAJA PENINSULA AND REACH THE NW MEXICAN  
COAST LATE MON NIGHT. ITS REMNANTS REACH NEAR EL PASO TEXAS BY  
SUNSET TUE AND ITS MOISTURE LIKELY TO MOVE INTO IL FOR THE  
THU/FRI TIME PERIOD. NBM POPS HAVE LOWERED FROM 2-3 INCHES TO  
1.5-2 INCHES AS THE SYSTEM APPEARS SLOWER MOVING IN AND AND  
FASTER MOVING OUT FRIDAY AFTERNOON/EVENING AS UPPER LEVEL TROF  
OPENS UP. SEVERE THUNDERSTORM RISK STILL APPEARS LOW LATE THIS  
WORK WEEK THOUGH MODERATE TO HEAVY RAINS STILL A RISK AS WPC  
DAY5 FOR THU/THU NIGHT HAS SLIGHT RISK OF EXCESSIVE RAINFALL  
OVER CENTRAL IL AND MARGINAL RISK IN SOUTHEAST IL.  
 
A 1027-1030 MB HIGH PRESSURE SETTLES INTO THE WESTERN GREAT  
LAKES FRIDAY NIGHT AND EASTERN GREAT LAKES BY SUNSET SAT  
BRINGING DRIER WX BACK TO THE AREA FRI NIGHT AND SAT. MODELS  
DIFFER WITH HANDLING NEXT SOUTHERN STREAM SYSTEM EARLY NEXT  
WEEK WITH ECMWF MUCH WETTER OVER CWA ON SUNDAY WHILE GFS AND GEM  
MODELS KEEP MOISTURE SOUTH OF CWA. NBM HAS 20-30% POPS SE OF THE  
IL RIVER ON SUNDAY. COOLER MORE FALL LIKE TEMPS RETURN FRIDAY  
THROUGH SUNDAY WITH HIGHS IN THE MID 60S TO LOWER 70S AND LOWS  
IN THE LOW TO MID 50S.  
 

 
   
AVIATION /06Z TAFS THROUGH 06Z TUESDAY/
 
 
ISSUED AT 1147 PM CDT SUN SEP 27 2026  
 
VFR WITH SCT HIGH CLOUDS THROUGH MONDAY. THERE IS A LOW CHANCE  
(30%) OF LOWERED VISIBILITIES IN FOG EARLY THIS MORNING,  
PARTICULARLY AT KCMI. WINDS CONTINUE LIGHT NORTHEAST.  
 

 
   
ILX WATCHES/WARNINGS/ADVISORIES
 
 
NONE.  
 

 
 

 
 
KEY MESSAGES...07  
DISCUSSION...07  
AVIATION...25  
 
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