175
FXUS63 KILX 120547
AFDILX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE LINCOLN IL
1247 AM CDT FRI JUN 12 2026
KEY MESSAGES
- SHOWERS AND THUNDERSTORMS WILL DIMINISH OVER SOUTHEAST IL
SOUTH OF I-70 DURING EARLY OVERNIGHT. A FEW STORMS COULD BE
STRONG TO SEVERE WITH GUSTY WINDS.
- MORE SHOWERS AND THUNDERSTORMS ARE LIKELY (60-80% CHANCE)
SATURDAY NIGHT, WITH A LEVEL 1 OF 5 (MARGINAL) RISK FOR
SEVERE WEATHER AND EXCESSIVE RAINFALL.
UPDATE
ISSUED AT 835 PM CDT THU JUN 11 2026
A SQUALL LINE OF SEVERE STORMS WAS RACING EASTWARD AROUND 60
MPH ACROSS CENTRAL IL LATE THIS AFTERNOON AND EARLY EVENING.
CURRENTLY THE LINE OF STORMS WAS ALONG AND JUST SOUTH OF I-72
AND STILL PRODUCING SEVERE STORMS WITH SEVERAL COUNTIES HAVING
SEVERE THUNDERSTORM WARNINGS AND GOING INTO WEST CENTRAL AND NW
INDIANA WHERE SOME TORNADO WARNINGS WERE IN EFFECT. THIS SQUALL
LINE HAD A HISTORY OF WIDESPREAD DAMAGING WINDS, AND SOME LARGE
HAIL AND TORNADOES OVER CENTRAL AND NORTHEAST IL. THIS LINE OF
STORMS IS MOVING QUICKER AND WILL LIKELY STAY SEVERE AS IT MOVES
INTO SOUTHEAST IL LATE THIS EVENING. VERY UNSTABLE AIR MASS
STILL AHEAD OF THESE STORMS WITH MLCAPES OF 2500-3500 J/KG AND
INCREASING BULK SHEAR VALUES MOVING INTO SOUTHEAST IL NEXT FEW
HOURS. THE CONVECTION WAS SE OF A BLOOMINGTON TO JACKSONVILLE
LINE AND THE FLOOD WATCH WILL BE ALLOW TO EXPIRE AT 9 PM CDT.
THE LATEST HRRR HAS LINE OF STRONG TO SEVERE STORMS MOVING INTO
FAR SOUTHEAST IL BETWEEN MIDNIGHT AND 1 AM AND ENDING IN SE IL
BETWEEN 3-4 AM. LOWS OVERNIGHT 55-60F FROM I-72 NORTH (COOLEST
IN GALESBURG) TO MID 60S IN SOUTHEAST IL.
DISCUSSION
ISSUED AT 230 PM CDT THU JUN 11 2026
***** SEVERE WEATHER OUTBREAK THIS EVENING *****
AT 230PM, TEMPERATURES AND DEWPOINTS ACROSS CENTRAL AND SOUTHEAST
ILLINOIS WERE IN THE MID-UPPER 80S AND MID 70S, RESPECTIVELY AMIDST
SOUTHERLY FLOW, EVAPOTRANSPIRATION "ET" (MOSTLY EVAPORATION THIS
EARLY IN THE GROWING SEASON), AND SUNSHINE. RAP MESOANALYSIS
SUGGESTS THIS IS CONTRIBUTING TO MLCAPE VALUES OF 1000-3500 J/KG - A
SHARP GRADIENT ACROSS THE AREA WITH HIGHER VALUES TO THE SOUTH.
SURFACE HEATING SHOULD CONTINUE TO BOOST BOTH TEMPERATURES AND
INSTABILITY AND REDUCE CONVECTIVE INHIBITION (CIN) THROUGHOUT THE
AFTERNOON AHEAD OF AN APPROACHING COLD FRONT, WHICH WILL SWEEP THE
AREA WEST-EAST DURING THE MID TO LATE EVENING HOURS. RAP/HRRR/NAM
SUGGEST MLCAPE WILL PEAK AROUND 4000-5000 J/KG WITH 35-45 KT DEEP
LAYER SHEAR AHEAD OF THAT FRONT, WHICH SHOULD PROVIDE SUFFICIENT
FORCING TO MAINTAIN THE ONGOING STORMS ACROSS WEST-CENTRAL IL AND
RESULT IN DEVELOPMENT FURTHER TO THE SOUTH. THIS HIGHLY VOLATILE
CONVECTIVE ENVIRONMENT SHOULD FAVOR ORGANIZED CONVECTION CAPABLE
INITIALLY OF ALL SEVERE HAZARDS (TORNADOES, LARGE HAIL, AND DAMAGING
WINDS), WITH AN INCREASING WIND AND QUASILINEAR CONVECTIVE SYSTEM
(QLCS) TORNADO THREAT AS STORMS GROW QUICKLY UPSCALE INTO BOWING
LINES. PWATS APPROACHING 2 INCHES WILL FAVOR PRECIP LOADING,
ESPECIALLY IN THE TALLER CORES WHICH WILL FEATURE MELTING HAIL,
WHILE STEEP MID LEVEL LAPSE RATES AND WIDE CAPE PROFILES WILL
ENHANCE POTENTIAL FOR RIJ FORMATION IN BOWING SEGMENTS; THIS WILL
INCREASE THE RISK FOR HIGH-END (75+ MPH) AND LONG-DURATION (20+
MINUTES) STRAIGHT-LINE WINDS WHICH WOULD RESULT IN SWATHS OF
ENHANCED DAMAGE (TREES DOWN, SHINGLE DAMAGE, POWER OUTAGES). SPC HAS
ISSUED A LEVEL 4 OF 5, "MODERATE," RISK FOR SEVERE WEATHER, DRIVEN
BY WIND AND TORNADOES, WHICH COULD BE STRONG NORTH OF A MACOMB TO
BLOOMINGTON LINE. WINDS AHEAD OF THESE STORMS MAY GUST UP TO 40 MPH
FROM THE SOUTH, AS DESCENDING HYDROMETEORS FROM ANVILS AID IN
MOMENTUM TRANSPORT FROM A 40-50 KT LLJ (STRONGEST OVER NORTHERN IL).
***** LOW RISK FOR FLASH FLOODING *****
WITH SOME LOCATIONS NORTH OF I-72 AND WEST OF I-57 HAVING RECEIVED
OVER 3 INCHES OF RAINFALL YESTERDAY (AND MULTIPLE ROUNDS OF HEAVY
RAINFALL IN DAYS PRIOR), THERE IS CONCERN THAT FLASH FLOODING COULD
OCCUR WITH STORMS THIS AFTERNOON AND EVENING. THIS IS ESPECIALLY
TRUE WITH THE ONGOING TRAINING STORMS NORTH OF A ROUGHLY MACOMB TO
EL PASO LINE. 3 HOUR FFG IN SOME OF THESE AREAS IS UNDER A HALF AN
INCH, AND WITH VARIOUS CAMS ADVERTISING 1 HOUR RAIN RATES >1 INCH IT
MAKES SENSE THERE COULD BE SOME ISSUES, ESPECIALLY IN URBAN AND POOR
DRAINAGE AREAS. A FLOOD WATCH WAS ISSUED FOR CASS TO DEWITT, AND
COUNTIES FURTHER NORTH, IN EFFECT UNTIL 9PM.
***** LESS WARM AND MUGGY STARTING TONIGHT *****
BEHIND THE COLD FRONT, CONDITIONS WILL TURN MUCH LESS HUMID AND,
WITH SOME CLEARING, TEMPERATURES ARE FORECAST TO FALL INTO THE MID
TO UPPER 50S OVERNIGHT WEST OF ROUGHLY I-57. HIGH TEMPERATURES
TOMORROW SHOULD ONLY CLIMB INTO THE LOW 80S, MAKING IT FEEL MUCH
MORE PLEASANT HEADING INTO THE WEEKEND. WARM AIR ADVECTION (WAA)
WILL BRING A SLIGHTLY MORE HUMID AIRMASS INTO THE REGION TOMORROW
NIGHT INTO SATURDAY AHEAD OF ANOTHER SHORTWAVE TROUGH, BUT
CONVECTION TO OUR SOUTHWEST SHOULD LIMIT THE NORTHWARD EXTENT OF
DEEP LAYER MOISTURE - RESULTING IN A LOW (ALBEIT NONZERO) RISK FOR
SEVERE WEATHER AND HEAVY RAINFALL SATURDAY/NIGHT IN OUR NECK OF THE
WOODS. BOTH SPC AND WPC HAVE US IN MARGINAL RISKS FOR EACH HAZARD.
BEHIND THAT SECOND FRONT, MUCH COOLER CONDITIONS RETURN, WITH NBM
ONLY GIVING A 15-30% CHANCE HIGH TEMPERATURES REACH 75 DEGREES ON
SUNDAY. TEMPERATURES ARE SLATED TO MODERATE GRADUALLY TOWARDS THE
MIDDLE OF NEXT WEEK, AS SOUTHWEST FLOW RETURNS AHEAD OF THE NEXT
UPPER LEVEL LOW PRESSURE SYSTEM.
AVIATION /06Z TAFS THROUGH 06Z SATURDAY/
ISSUED AT 1245 AM CDT FRI JUN 12 2026
VFR CONDITIONS ARE FORECAST TO OCCUR NEXT 24 HOURS THROUGH
06Z/SAT ACROSS THE CENTRAL IL AIRPORTS. A COLD FRONT PUSHING
INTO SOUTHEAST IL EARLY OVERNIGHT WILL PUSH INTO THE OHIO RIVER
VALLEY BY MORNING. ITS CONVECTION WAS SOUTHEAST OF I-70 AND WILL
CONTINUE MOVING AWAY FROM THE CENTRAL IL AIRPORTS. CLEARING
SKIES NOTED FROM I-55 WEST WHILE MID LEVEL CLOUDS OVER DEC AND
CMI SHOULD SCATTERED OUT/CLEAR NEXT FEW HOURS. WEST TO NW WINDS
HAVE DIMINISH TO 5-10 KTS AND WILL GENERALLY BE AROUND 10 KTS ON
SATURDAY. WINDS VEER SOUTH TO SSW AROUND 5 KTS SAT EVENING.
ILX WATCHES/WARNINGS/ADVISORIES
NONE.
KEY MESSAGES...BUMGARDNER
UPDATE...07
DISCUSSION...BUMGARDNER
AVIATION...07
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