124
FXUS63 KILX 082339
AFDILX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE LINCOLN IL
639 PM CDT WED JUL 8 2026
KEY MESSAGES
- THUNDERSTORMS WILL BRING A RISK FOR DAMAGING WIND GUSTS ON
THURSDAY AFTERNOON AND EVENING, WITH THE GREATEST CHANCES FOR
DAMAGING WINDS SOUTH OF I-72.
- PERIODS OF HEAVY RAINFALL WILL BE A CONCERN FROM THURSDAY
AFTERNOON THROUGH SATURDAY. THE GREATEST CONCERN FOR HEAVY
RAINFALL AND FLOODING POTENTIAL WILL ALSO BE SOUTH OF I-72,
WHERE THERE IS A 20-30% CHANCE OF RAINFALL EXCEEDING 2 INCHES.
- POTENTIAL EXISTS FOR EXTREME HEAT AROUND THE MIDDLE OF NEXT
WEEK, THOUGH SOME UNCERTAINTY REMAINS.
DISCUSSION
ISSUED AT 241 PM CDT WED JUL 8 2026
** THUNDERSTORM POTENTIAL THURSDAY **
AN UNSTABLE AIRMASS WITH MLCAPE PERHAPS IN EXCESS OF 2000 J/KG
WILL RESIDE SOUTH OF AN APPROACHING FRONTAL BOUNDARY ON THURSDAY
AFTERNOON. IT IS ANTICIPATED THAT ONE OR MORE MCVS EMANATING
FROM OVERNIGHT CONVECTIVE ACTIVITY IN THE CENTRAL PLAINS WILL
SERVE AS FORCING MECHANISMS TO HELP INITIATE CONVECTION ON
THURSDAY AFTERNOON IN CENTRAL/SOUTHEAST ILLINOIS. THOUGH SHEAR
EVEN INTO THURSDAY MORNING MAY BE ON THE WEAK SIDE, THE MCV(S)
SHOULD AT LEAST LOCALLY ENHANCE 0-6 KM SHEAR BY THURSDAY
AFTERNOON/EVENING. IN ADDITION, FORECAST DCAPE VALUES ARE IN
EXCESS OF 1100-1200 J/KG, PARTICULARLY SOUTH OF I-72 WHERE THE
MOST LIKELY TRACK OF AN MCV IS. ALL OF THESE FACTORS TOGETHER
INDICATE ELEVATED DAMAGING WIND POTENTIAL PARTICULARLY SOUTH OF
I-72, WITH AN SPC LEVEL 2 SEVERE RISK THERE.
IT IS WORTH NOTING THAT THERE IS SOME VARIABILITY CONCERNING
THE PATH/DEVELOPMENT OF POTENTIAL MCVS, WITH GREATER CONVECTIVE
DEVELOPMENT PERHAPS OCCURING NORTH OR SOUTH OF THE MOST LIKELY
TRACK.
** HEAVY RAINFALL THURSDAY - SATURDAY **
ON THURSDAY, MULTIPLE MODEL SOLUTIONS DEPICT PRECIPITABLE WATER
VALUES IN EXCESS OF 2 INCHES ACROSS MUCH OF CENTRAL AND
SOUTHEAST ILLINOIS. STEERING FLOW APPEARS TO BE ORIENTED
PERPENDICULAR TO THE INITIAL WAVE OF RAINFALL THURSDAY
AFTERNOON, BUT A SECOND WAVE PERHAPS ASSOCIATED WITH A SECOND
MCV LATER IN THE EVENING/OVERNIGHT MAY PROVIDE MORE OF A HEAVY
RAIN THREAT WITH TRAINING ELEMENTS BECOMING MORE LIKELY. THE
PATH OF THE MCV(S) ON THURSDAY, AS WELL AS ASSOCIATED CONVECTIVE
DEVELOPMENT THURSDAY AFTERNOON/EVENING, WILL BE DETERMINING
FACTORS IN HOW FAR SOUTH THE EFFECTIVE FRONTAL BOUNDARY PUSHES
GOING INTO FRIDAY. SHOULD THAT BOUNDARY BECOME STALLED AT SOME
POINT, THE HEAVY RAIN THREAT WILL INCREASE FURTHER.
CHANCES OF GREATER THAN 2 INCHES OF RAINFALL AT ANY GIVEN POINT
NEAR AND SOUTH OF I-72 THROUGH SATURDAY NIGHT CURRENTLY ARE IN
THE 20-30% RANGE. ISOLATED TOTALS IN EXCESS OF 4-5 INCHES ARE
NOT OUTSIDE THE REALM OF POSSIBILITY, THOUGH CONFIDENCE IS LOW
REGARDING WHERE THESE ISOLATED HIGH TOTALS MAY BE MOST LIKELY.
** MIDDLE OF NEXT WEEK **
SOME UNCERTAINTY REMAINS REGARDING THE EVOLUTION OF THE PATTERN
FOR NEXT WEEK. MOST SOLUTIONS DEPICT A STRONG 500 MB RIDGE OVER
THE CENTRAL AND NORTHERN PLAINS, WITH VARIABILITY REGARDING HOW
FAR EAST THE CENTER OF THAT RIDGE SPREADS AND TO WHAT DEGREE THE
RIDGE INFLUENCES WEATHER OVER CENTRAL AND SOUTHEAST ILLINOIS. A
TROUGH CENTERED NEAR HUDSON BAY WILL ALSO HAVE THE POTENTIAL TO
PROVIDE SOME MODERATING INFLUENCE TO THE RIDGE, AS WELL AS A
CHANCE FOR STORMS IN NORTHWEST FLOW. WPC CLUSTER ALGORITHM FOR
THU JUL 16 CURRENTLY SHOWS ABOUT 20% OF GLOBAL SOLUTIONS WITH
THE STRONGER HUDSON BAY TROUGH, WITH ABOUT 80% OF SOLUTIONS
HAVING A STRONGER CENTRAL PLAINS RIDGE AND/OR A WEAKER TROUGH TO
THE NORTHWEST. CPC HAS THE MIDWEST IN A SLIGHT-MODERATE RISK FOR
EXTREME HIGH TEMPERATURES DURING THIS TIME PERIOD.
AVIATION /00Z TAFS THROUGH 00Z FRIDAY/
ISSUED AT 639 PM CDT WED JUL 8 2026
VFR CONDITIONS WILL PREVAIL AT ALL SITES THROUGH THE NIGHT AND
TOMORROW. SCATTERED CU AROUND 3.5KFT WILL DISSIPATE THIS EVENING
AND LEAVE MOSTLY CLEAR SKIES THROUGH THE NIGHT. ADDITIONAL CU
WILL DEVELOP TOMORROW LATE MORNING AND CONTINUE THROUGH THE
AFTERNOON. A WEAK FRONT AND REMNANTS OF AN OVERNIGHT MCS WILL
MOVE ACROSS THE AREAS TOMORROW AFTERNOON AND WITH THE HEATING
TOMORROW, SCATTERED THUNDERSTORMS ARE POSSIBLE AT ALL SITES.
HAVE ADDED PROB30 AT ALL SITES FOR AFTERNOON THUNDERSTORMS WITH
VFR CIGS, BUT MVFR VIS DURING THE STORMS. WINDS WILL BE LIGHT
AND VARIABLE TONIGHT AND THEN BECOME WEST-SOUTHWESTERLY TOMORROW
AT LESS THAN 10KTS.
ILX WATCHES/WARNINGS/ADVISORIES
NONE.
KEY MESSAGES...AAT
DISCUSSION...AAT
AVIATION...AUTEN
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