084
FXUS63 KILX 271935
AFDILX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE LINCOLN IL
235 PM CDT MON APR 27 2026
KEY MESSAGES
- THERE IS A LEVEL 3 OF 5 (ENHANCED) RISK FOR SEVERE WEATHER THIS
EVENING. DAMAGING WINDS, LARGE HAIL, A COUPLE TORNADOES, AND
FLASH FLOODING ARE ALL CONCERNS, ESPECIALLY NEAR AND SOUTH OF
I-70.
- THERE IS A 30-50% CHANCE FOR FROST FRIDAY NIGHT. TENDER
VEGETATION MAY NEED TO BE COVERED IN ORDER TO PREVENT DAMAGE.
DISCUSSION
ISSUED AT 226 PM CDT MON APR 27 2026
***** SEVERE WEATHER THIS EVENING *****
MID LEVEL WATER VAPOR SATELLITE REVEALS A NEGATIVELY TILTED UPPER
LEVEL TROUGH SPINNING OVER THE MIDWEST. AT THE SURFACE, WPC HAS
ANALYZED A 996MB LOW IN EASTERN IOWA WHICH IS FORECAST TO LIFT
NORTHEASTWARD ACROSS WISCONSIN THIS EVENING. MUCH OF THE WARM SECTOR
HAS BEEN WORKED OVER AT THIS POINT VIA A MORNING-EARLY AFTERNOON
MCS, BUT THESE STORMS LEFT AN OUTFLOW BOUNDARY NEAR/SOUTH OF THE I-
70 CORRIDOR WHICH WILL SERVE AS A DIFFERENTIAL HEATING/CONVERGENCE
ZONE FOR RENEWED STORMS LATER THIS AFTERNOON. A WAKE LOW CONTINUES
TO FOSTER WIND GUSTS UP TO 35MPH FROM THE SOUTHEAST, WHICH SHOULD
HELP MAINTAIN STABLE LOW LEVELS FURTHER NORTH. NONETHELESS, A FEW
ELEVATED STORMS COULD GENERATE LOCALLY SEVERE HAIL AND WIND IN
THOSE AREAS. MEANWHILE, SOUTH OF THE I-70 CORRIDOR, DEWPOINTS
SHOULD SURGE INTO THE MID-UPPER 60S WHILE A 50 KT LLJ MAINTAINS
40-55 KT EFFECTIVE BULK WIND SHEAR AND 400-700 (679 ON THE VWX
VAD PROFILER) M^2/S^2 0-3KM SRH VIA STRONGLY CYCLONICALLY
CURVED HODOGRAPHS. CAMS GENERALLY SUGGEST CONVECTIVE ACTIVITY
DEVELOPING UPSTREAM OVER THE NEXT COUPLE HOURS AND MOVING
THROUGH THIS ENVIRONMENT DURING THE EVENING WILL START DISCRETE
AND EVENTUALLY GROW UPSCALE INTO ANOTHER MCS. HENCE, THE INITIAL
HAZARDS WILL BE VERY LARGE HAIL AND TORNADOES, WITH THE RISK
TRANSITIONING TO DAMAGING WINDS, LOCALLY SEVERE HAIL, AND QLCS
TORNADOES WITH TIME. TRAINING STORMS WILL POSE A RISK FOR FLASH
FLOODING (REFS AND HREF ENSEMBLE MAX PRECIP HAVE SWATHS OF 4+
INCHES OF RAIN FALLING IN <6 HOURS), FOR WHICH WE HAVE ISSUED A
FLOOD WATCH WHICH EXTENDS THROUGH 10PM. A TORNADO WATCH IS IN
EFFECT FOR EFFINGHAM TO CRAWFORD COUNTIES AND AREAS FURTHER
SOUTH, WHERE THE CHANCE OF SURFACE BASED (AND HENCE POTENTIALLY
TORNADIC) STORMS IS HIGHEST. STORMS SHOULD EXIT THE ILX COUNTY
WARNING AREA BY 11PM, WHILE A COOLER AND MORE STABLE AIRMASS
ARRIVES FROM THE WEST-NORTHWEST BEHIND A COLD FRONT.
***** DRY CONDITIONS LIKELY WEDNESDAY AND BEYOND *****
ANOTHER SHORTWAVE WILL LIFT NORTHEAST THROUGH THE AREA TOMORROW
NIGHT, BRINGING ANOTHER OPPORTUNITY FOR SOME RAIN AND PERHAPS A
RUMBLE OF THUNDER. THANKFULLY QPF WITH THIS SYSTEM IS LIGHTER, WITH
A LOW (<20%) CHANCE FOR AN ADDITIONAL INCH OF RAINFALL. SINCE THIS
WILL OCCUR AROUND 24 HOURS AFTER THIS EVENING'S HEAVY RAINFALL IN
SOUTHEAST ILLINOIS, THE GROUND MAY HAVE SOME TIME TO ABSORB THE
WATER, THOUGH WE'LL STILL BE KEEPING ONE EYE ON IT.
BY WEDNESDAY MORNING, A DRIER PATTERN SHOULD TAKE HOLD OF THE
REGION, WITH LESS THAN A 20% CHANCE FOR RAIN THROUGH THE WEEKEND.
HIGH TEMPERATURES EACH DAY ARE FORECAST IN THE 60S, WITH LOCATIONS
NEAR AND NORTH OF THE I-74 CORRIDOR POTENTIALLY (60% CHANCE) NOT
CLIMBING OUT OF THE 50S ON FRIDAY. THE NATIONAL BLEND OF MODELS
(NBM) INDICATES A 30-50% CHANCE TEMPERATURES FALL BELOW 37 DEGF
FRIDAY NIGHT INTO SATURDAY MORNING, WHICH SHOULD BE COLD ENOUGH FOR
FROST GIVEN THE EXPECTED LIGHT WINDS.
AVIATION /18Z TAFS THROUGH 18Z TUESDAY/
ISSUED AT 1258 PM CDT MON APR 27 2026
A THUNDERSTORM COMPLEX WILL MOVE EAST OF THE AIRFIELDS OVER THE
NEXT COUPLE HOURS, WITH A 30-40% CHANCE OF REDEVELOPMENT NORTH
TO IMPACT BMI AND PIA (HIGHER CHANCES AT THE OTHER AIRFIELDS) AFTER
22Z. IN THE WAKE OF THE MORNING STORMS, A BRIEF PERIOD OF
SOUTHEAST WIND GUSTS TO 40 KT ARE POSSIBLE (20-30% CHANCE); TAFS
WILL BE AMENDED FOR THIS AS NECESSARY. OTHERWISE, WINDS WILL
BLOW FROM THE SOUTH-SOUTHEAST AROUND 15-20 KT WITH GUSTS UP TO
30 KT THROUGH LATE AFTERNOON, VEERING TO SOUTHWESTERLY AND
EASING THIS EVENING, AND THEN VEERING MORE SHARPLY TO A WEST-
NORTHWESTERLY DIRECTION TONIGHT BEHIND A COLD FRONT. THERE WILL
ALSO BE A 50-60% CHANCE FOR MVFR CEILINGS BEHIND THAT FRONT
AFTER AROUND 06Z.
ILX WATCHES/WARNINGS/ADVISORIES
FLOOD WATCH UNTIL 10 PM CDT THIS EVENING FOR ILZ052>057-
061>063-066>068-071>073.
KEY MESSAGES...BUMGARDNER
DISCUSSION...BUMGARDNER
AVIATION...BUMGARDNER
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