877  
FXUS63 KLOT 032343  
AFDLOT  
 
AREA FORECAST DISCUSSION  
NATIONAL WEATHER SERVICE CHICAGO/ROMEOVILLE, IL  
643 PM CDT TUE JUN 3 2025  
   
KEY MESSAGES
 
 
- STRONG TO SEVERE WIND GUSTS FROM AN ORGANIZED THUNDERSTORM  
COMPLEX WILL BE POSSIBLE THIS EVENING, MAINLY NEAR AND WEST  
OF THE I-39 CORRIDOR.  
 
- A BAND OF SHOWERS AND SOME THUNDERSTORMS WILL MOVE EASTWARD  
ACROSS THE AREA TONIGHT THROUGH WEDNESDAY.  
 
- TRENDING DRIER WITH SEASONABLE TO SEASONABLY COOL CONDITIONS  
LATE THIS WEEK AND INTO THE WEEKEND.  
 

 
   
DISCUSSION
 
 
ISSUED AT 347 PM CDT TUE JUN 3 2025  
 
THROUGH WEDNESDAY:  
 
PLEASE REFERENCE THE MESOSCALE DISCUSSION ABOVE FOR INFORMATION  
ABOUT THE STRONG TO SEVERE THUNDERSTORM POTENTIAL THIS EVENING.  
 
AFTER THE MCS DECAYS THIS EVENING, AN ELONGATED BAND OF RAIN  
STREAMING NORTHEASTWARD ACROSS AN EASTWARD-INCHING FRONTAL ZONE  
WILL PERSIST IN OUR FORECAST AREA THROUGH THE OVERNIGHT HOURS  
AND INTO THE DAYTIME TOMORROW. SOME EMBEDDED LIGHTNING COULD  
OCCUR LATE THIS EVENING INTO THE OVERNIGHT HOURS, BUT IN  
GENERAL, THE OVERALL LIKELIHOOD OF LIGHTNING WILL CONTINUE TO  
STEADILY DIMINISH THROUGH THE NIGHT AND INTO TOMORROW MORNING.  
AREAS STILL NEAR AND SOUTH OF THE TRUE COLD FRONT BY MID-DAY  
TOMORROW (LIKELY LOCATIONS SOUTH OF I-80, BUT ESPECIALLY  
LOCATIONS SOUTH OF THE KANKAKEE RIVER) SHOULD THEN SEE A  
RENEWED POTENTIAL FOR THUNDERSTORMS DURING THE AFTERNOON AS PRE-  
FRONTAL WARM AIR ADVECTION AND FILTERED SUNSHINE CONTRIBUTE TO  
DIURNAL DESTABILIZATION. QUESTIONS STILL REMAIN REGARDING  
WHETHER THE BETTER INSTABILITY WILL GET AS FAR NORTH AS OUR  
SOUTHEASTERN CWA. IF IT DOES, THEN COULDN'T RULE OUT A STRONG  
STORM OR TWO OCCURRING IN OUR SOUTHEASTERN COUNTIES, BUT THE  
OVERALL BETTER CHANCES FOR THIS SHOULD REMAIN TO OUR SOUTH AND  
EAST.  
 
OTHERWISE, FALL-LIKE CONDITIONS CAN BE EXPECTED TOMORROW NORTH  
OF THE COLD FRONT WITH ANAFRONTAL RAIN, STRATUS, AND  
TEMPERATURES LARGELY IN THE MID 50S TO MID 60S. THE RAIN AND LOW  
CLOUDS SHOULD CLEAR OUT FASTER IN OUR FAR NORTHERN CWA  
(INCLUDING IN THE ROCKFORD AREA), WHICH COULD ALLOW DAYTIME  
TEMPERATURES THERE TO CLIMB INTO THE LOW 70S. HOWEVER, SMOKE  
MODELS INDICATE THAT ANOTHER PLUME OF CANADIAN WILDFIRE SMOKE  
SHOULD DESCEND INTO THE AREA BEHIND THE ANAFRONTAL RAIN, WHICH  
WILL LEAD TO HAZY SKIES ONCE AGAIN WHEREVER THE STRATUS HAS  
CLEARED OUT, AND COULD POTENTIALLY RESULT IN SOME SMOKE  
CONCENTRATIONS BEING OBSERVED AT GROUND LEVEL ONCE AGAIN AS WELL.  
 
OGOREK  
 
WEDNESDAY NIGHT THROUGH MONDAY:  
 
WEDNESDAY'S COLD FRONT WILL CONTINUE TO SAG SOUTHWARD WEDNESDAY  
NIGHT, WITH THE REMAINING SOUTHEAST PORTIONS OF THE CWA CLEARED  
OF THE FRONT BY MID-EVENING AND REMAINING SHOWERS AFTER  
MIDNIGHT. THE FRONT WILL SETTLE JUST NORTH OF THE OHIO RIVER  
VALLEY BY THURSDAY MORNING AS SURFACE HIGH PRESSURE DRIFTS  
ACROSS THE UPPER GREAT LAKES. THIS WILL FAVOR A DRY AND MOSTLY  
SUNNY DAY ON THURSDAY WITH HIGHS IN THE MID TO UPPER 70S INLAND  
AND 60S ALONG THE LAKE.  
 
CONSENSUS GUIDANCE IS FOR A WAVE ACROSS THE CENTRAL ROCKIES TO  
PICKUP OR ABSORB AT LEAST SOME ENERGY FROM AN UPPER-LEVEL LOW  
OVER THE SOUTHWEST U.S. WEDNESDAY INTO THURSDAY. A WEAK SURFACE  
LOW DEVELOPING FROM CONVECTIVE FEEDBACK OVER THE CENTRAL GREAT  
PLAINS THURSDAY EVENING WILL TRAVERSE THE FRONT ON FRIDAY.  
GUIDANCE HAS COME INTO SOMEWHAT BETTER AGREEMENT THAT THE MAIN  
IMPACTS FROM THIS SYSTEM DEVELOPING ALONG THE FRONT WILL REMAIN  
SOUTH OF MUCH OF THE FORECAST AREA, THOUGH SOME SHOWERS COULD  
BRUSH THE SOUTHERN CWA FRIDAY AFTERNOON AND EVENING. OTHERWISE,  
SEASONABLY COOL CONDITIONS UNDER PARTLY TO MOSTLY CLOUDY SKIES  
CAN BE EXPECTED ON FRIDAY.  
 
HIGH PRESSURE ACROSS THE UPPER MISSISSIPPI RIVER VALLEY ON  
SATURDAY WILL PRODUCE SEASONABLE CONDITIONS AND DRY WEATHER. AN  
UPPER-LEVEL LOW OVER THE FAR NORTHERN GREAT LAKES WILL THEN PUSH  
A COLD FRONT WITH THE POTENTIAL FOR SHOWERS AND A FEW STORMS  
ACROSS THE AREA LATE SUNDAY INTO MONDAY MORNING.  
 
KLUBER  
 

 
   
AVIATION /00Z TAFS THROUGH 06Z THURSDAY/
 
 
ISSUED AT 643 PM CDT TUE JUN 3 2025  
 
FORECAST CONCERNS INCLUDE...  
 
CHANCE OF THUNDERSTORMS THIS EVENING, MAINLY NW IL AND RFD.  
WIND SHIFT TO NORTHEAST WEDNESDAY MORNING.  
SHOWERS WITH IFR CIGS, MVFR VIS WEDNESDAY MORNING.  
POSSIBLE SMOKE/HAZE WEDNESDAY AFTERNOON WITH POSSIBLE MVFR VIS.  
 
SCATTERED THUNDERSTORMS WILL MOVE ACROSS NORTHWEST IL AND RFD  
THIS EVENING. SOME OF THESE STORMS MAY BE STRONG/SEVERE WITH  
ERRATIC/GUSTY WINDS. THIS ACTIVITY IS EXPECTED TO DISSIPATE  
QUICKLY AS IT MOVES ACROSS THE REST OF NORTHEAST IL DURING THE  
MID/LATE EVENING, EVENTUALLY ARRIVING AS SHOWERS OVERNIGHT FOR  
THE CHICAGO TERMINALS. THERE MAY BE A SEVERAL HOUR PERIOD OF  
LIGHT TO MODERATE RAIN WEDNESDAY MORNING AND THEN THE PRECIP IS  
EXPECTED TO SHIFT SOUTH OF THE TERMINALS. THERE MAY BE A FEW  
THUNDERSTORMS WELL SOUTH OF THE TERMINALS WEDNESDAY AFTERNOON.  
 
MVFR CIGS WILL BE POSSIBLE WITH ANY SHOWERS/THUNDERSTORMS THIS  
EVENING INTO THE EARLY OVERNIGHT HOURS AND THEN PREVAILING IFR  
CIGS ARE EXPECTED TO DEVELOP IN THE PREDAWN HOURS AND CONTINUE  
THROUGH MID/LATE WEDNESDAY MORNING, SLOWLY LIFTING AND THEN  
SCATTERING OUT FROM NORTH TO SOUTH WEDNESDAY AFTERNOON.  
 
SOUTHWEST WINDS WILL CONTINUE THIS EVENING WITH GUSTS INTO THE  
25-30 KT RANGE THROUGH SUNSET. SPEEDS AND GUSTS WILL THEN SLOWLY  
DIMINISH THROUGH THE LATE EVENING AND OVERNIGHT. A COLD FRONT  
WILL MOVE SOUTH ACROSS THE AREA SHIFTING WINDS NORTHERLY ACROSS  
NORTHWEST IL AFTER MIDNIGHT AND THEN SHIFTING WINDS TO THE  
NORTHEAST FOR THE CHICAGO TERMINALS AROUND DAYBREAK WEDNESDAY  
MORNING. WINDS ARE THEN EXPECTED TO REMAIN NORTHEAST FOR THE  
REST OF THE PERIOD.  
 
SMOKE FROM CANADIAN WILDFIRES MAY SPREAD ACROSS THE AREA  
WEDNESDAY AFTERNOON, AT THE SURFACE WITH MVFR VIS POSSIBLE.  
CONFIDENCE IS VERY LOW WITH LIMITED GUIDANCE. FOR NOW, HAVE NO  
MENTION IN THE FORECAST, BUT TRENDS WILL NEED TO BE MONITORED  
WITH LATER FORECASTS. CMS  
 

 
   
MARINE
 
 
ISSUED AT 312 AM CDT TUE JUN 3 2025  
 
POTENTIAL EXISTS FOR A PERIOD OF NEAR GALE TO LOW END GALE  
FORCE SOUTH-SOUTHWEST WINDS THIS AFTERNOON AND EVENING. THERE IS  
SOME UNCERTAINTY REGARDING JUST HOW STRONG THE WINDS WILL GET  
GIVEN THE INCREASING CLOUD COVER, SO OPTED TO JUST MAINTAIN  
MENTION OF GALE FORCE GUSTS AND HOLD OFF ON A GALE WARNING. IF  
IT BECOMES CLEAR THAT THERE WILL BE A PERIOD OF SOLID GALES,  
THEN A SHORT FUSED GALE WARNING COULD BE NEEDED FOR THE  
NEARSHORE WATERS FOR THIS AFTERNOON AND EVENING. THE STRONGEST  
WINDS AND ANY GALES WOULD LIKELY BE CONFINED TO AREAS CLOSE TO  
THE SHORE WITH A STRONGLY STABLE MARINE LAYER LIMITING THE  
MAGNITUDE OF WINDS/GUSTS FARTHER FROM THE SHORE.  
 
- IZZI  
 

 
   
LOT WATCHES/WARNINGS/ADVISORIES
 
 
IL...BEACH HAZARDS STATEMENT UNTIL 7 PM CDT THIS EVENING FOR ILZ006-  
ILZ103.  
 
IN...NONE.  
LM...GALE WARNING UNTIL 10 PM CDT THIS EVENING FOR THE IL AND IN  
NEARSHORE WATERS.  
 

 
 

 
 
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