297
FXUS63 KLOT 040019
AFDLOT
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE CHICAGO/ROMEOVILLE, IL
719 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.
MESOSCALE
ISSUED AT 719 PM CDT TUE JUN 3 2025
QUICK UPDATE TO THE PREVIOUS DISCUSSION BELOW. WHILE THE SEVERE
THREAT IS EXPECTED TO WANE WITH EASTWARD EXTENT ACROSS NORTHERN
IL AFTER 9 PM, WE HAVE OPTED TO EXPAND THE SEVERE THUNDERSTORM
WATCH TO INCLUDE ONE MORE TIER OF COUNTIES TO THE EAST (BOONE,
DEKALB AND LASALLE).
MESOSCALE
ISSUED AT 649 PM CDT TUE JUN 3 2025
A SEVERE THUNDERSTORM WATCH CONTINUES FOR NORTHWESTERN SECTIONS OF
IL THIS EVENING. THIS INCLUDES AREAS AS FAR EAST AS LEE, OGLE AND
WINNEBAGO COUNTIES IN NORTHWESTERN IL.
WE CONTINUE TO CLOSELY MONITOR THE SEVERE MCS CURRENTLY TRACKING
NORTHEASTWARD ACROSS THE MISSISSIPPI SOUTH OF THE QUAD CITIES.
THIS LINE CONTINUES TO DISPLAY SIGNS OF STRONG STRAIGHT LINE WIND
GUSTS (60+ MPH) AND QLCS TORNADOES ALONG ITS LEADING EDGE. THIS IS
PARTICULARLY THE CASE WITH THE NORTHEASTWARD BOW SEGMENTS MOVING
ACROSS HENDERSON COUNTY IN IL, AND DES MOINES AND LOUISA COUNTIES
IN FAR SOUTHEASTERN IA. THE NORTHEASTWARD MOVEMENT OF THIS
DANGEROUS LINE OF STORMS (UP TO 50 MPH) WILL PUT PARTS OF LEE,
OGLE AND WINNEBAGO COUNTIES IN THE PATH OF THE STORMS IN THE 8 TO
9 PM TIMEFRAME. STRONG DAMAGING WINDS WILL CONTINUE TO BE THE
PRIMARY THREAT THROUGH 9 PM, THOUGH A TORNADO OR TWO CANNOT BE
RULED OUT.
THE SEVERE THREAT IS EXPECTED TO WANE QUICKLY AFTER 9 PM AS THE
STORMS BEGIN TO MOVE INTO A LESS FAVORABLE THERMODYNAMIC
ENVIONRMENT EAST OF THE I-39 CORRIDOR. THE CURRENT WATCH AREA
THUS CONTINUES TO COVER THE MAIN THREAT AREA RATHER WELL, AND
THERE ARE CURRENTLY NO PLANS TO EXPAND THE SEVERE WATCH FARTHER TO
THE EAST.
KJB
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...NONE.
IN...NONE.
LM...GALE WARNING UNTIL 10 PM CDT THIS EVENING FOR THE IL AND IN
NEARSHORE WATERS.
VISIT US AT WEATHER.GOV/CHICAGO
CLICK HERE TO GO TO PREVIOUS BULLETINS.
Main Text Page