698
FXUS63 KILX 190547
AFDILX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE LINCOLN IL
1247 AM CDT TUE MAY 19 2026
KEY MESSAGES
- REPEATING ROUNDS OF SHOWERS AND STORMS COULD CAUSE FLASH
FLOODING SOUTH OF A SHELBYVILLE TO PARIS LINE THROUGH THIS
EVENING. A FLOOD WATCH IS IN EFFECT FOR THESE AREAS.
- ADDITIONAL THUNDERSTORMS WILL DEVELOP ALONG AN ADVANCING COLD
FRONT ON TUESDAY, WITH A SLIGHT RISK (LEVEL 2 OF 5) FOR SEVERE
STORMS EAST OF INTERSTATE 55. DAMAGING WINDS, LARGE HAIL, AND
HEAVY RAINFALL WOULD BE THE MOST LIKELY HAZARDS.
DISCUSSION
ISSUED AT 223 PM CDT MON MAY 18 2026
A LINE OF SHOWERS AND THUNDERSTORMS HAS STALLED OUT SOUTH OF THE I-
72 CORRIDOR THIS AFTERNOON. ALTHOUGH WIND SHEAR HAS INCREASED OVER
THIS AREA SINCE THIS MORNING, INSTABILITY HAS SIGNIFICANTLY WANED
AND HAS PREVENTED STORMS FROM LARGELY BECOMING ORGANIZED. DESPITE
THIS, CANNOT COMPLETELY RULE OUT A STRONG UPDRAFT OR TWO OVER THE
NEXT FEW HOURS IN FAR SOUTHEAST ILLINOIS WHERE RAP MESOANALYSIS
SHOWS SBCAPE OF 1000+ J/KG. IF ANY STRONG STORMS DO OCCUR, DAMAGING
WINDS WOULD BE POSSIBLE. THE MAIN THREAT THROUGH THE EVENING WILL BE
HEAVY RAINFALL WITH PWATS UP AROUND 1.5 TO 2 INCHES AND HOURLY
RAINFALL RATES UP AROUND 1 INCH IN THE HEAVIEST OF STORMS. A FLOOD
WATCH HAS BEEN ISSUED FOR AREAS SOUTH OF A SHELBYVILLE TO PARIS LINE
THROUGH THIS EVENING.
FURTHER WEST, ADDITIONAL THUNDERSTORMS HAVE DEVELOPED OVER THE
CENTRAL PLAINS AHEAD OF A COLD FRONT AND WILL TRACK EAST THROUGH
TONIGHT, APPROACHING WESTERN ILLINOIS SOMETIME AFTER MIDNIGHT. THESE
STORMS SHOULD WEAKEN AS THEY ENTER THE AREA DUE TO LACK OF
INSTABILITY, THOUGH THEY COULD STILL PRODUCE GUSTY SUBSEVERE WINDS
AS THEY TRACK THROUGH THE WESTERN HALF OF THE STATE. MOST OF THE
SHOWER AND STORM ACTIVITY SHOULD SUBSIDE BY OR BEFORE DAYBREAK.
THE COLD FRONT WILL APPROACH THE I-55 CORRIDOR AROUND MIDDAY TUESDAY
AND BE THE FOCUS FOR ADDITIONAL STORM DEVELOPMENT BY AFTERNOON.
HOWEVER, ONE LIMITING FACTOR WILL BE HOW LONG CLOUD COVER FROM THE
OVERNIGHT STORMS LINGERS, WHICH WOULD ULTIMATELY LIMIT OUR
DESTABILIZATION POTENTIAL. CAMS SUGGEST DESTABILIZATION WILL BE MOST
LIKELY IN EAST-CENTRAL AND SOUTHEAST ILLINOIS BY MID TO LATE
AFTERNOON IN A MODERATELY SHEARED ENVIRONMENT. HOWEVER, THIS APPEARS
TO BE HIGHLY CONDITIONAL AT THIS POINT. IF STORMS DO DEVELOP,
DAMAGING WINDS, LARGE HAIL, AND HEAVY RAINFALL WILL BE THE PRIMARY
CONCERNS.
A DRIER AND COOLER PERIOD SHAPES UP FOR MIDWEEK AS HIGH PRESSURE
RIDGING SLIDES THROUGH THE UPPER MIDWEST. THIS WILL BE RELATIVELY
SHORT-LIVED AS UPPER TROUGHING MOVES INTO THE CENTRAL US AND
SHORTWAVE ENERGY SENDS SEVERAL ROUNDS OF PRECIPITATION THROUGH
ILLINOIS THIS WEEKEND INTO EARLY NEXT WEEK. WHILE THE SEVERE WEATHER
RISK APPEARS LOW THROUGH THIS PERIOD, BETTER MOISTURE/INSTABILITY
BUILDING BY LATE WEEKEND/EARLY NEXT WEEK WILL SUPPORT
THUNDERSTORMS AT TIMES.
AVIATION /06Z TAFS THROUGH 06Z WEDNESDAY/
ISSUED AT 1247 AM CDT TUE MAY 19 2026
A LINE OF THUNDERSTORMS AHEAD OF AN APPROACHING COLD FRONT WILL
MOVE INTO THE WESTERN CENTRAL IL TERMINALS KPIA, KSPI, AND KBMI
FROM 08Z-12Z, ALTHOUGH THESE STORMS ARE EXPECTED TO BE IN A
WEAKENING STATE AND LIKELY WILL NOT MAINTAIN AS THEY HEAD INTO
KDEC AND KCMI TOWARD EAST-CENTRAL IL. HAVE INCLUDED TEMPO FOR
TSRA AT THE WESTERN TERMINALS BETWEEN 08Z AND 12Z, BUT ONLY VCSH
AND PROB30 FOR SHRA AT THE EASTERN TERMINALS 15Z-19Z. HOWEVER,
REDEVELOPMENT OF STORMS MAY BEGIN DURING THE AFTERNOON AT THE
EASTERN SITES WITH DIURNAL HEATING, AND HAVE INCLUDED PROB30 FOR
TSRA 19Z-24Z. MVFR CIGS OR BRIEFLY WORSE CAN BE EXPECTED WITH
TSRA, AND AN AREA OF MVFR CIGS IS EXPECTED TO TRAIL THE COLD
FRONT, ARRIVING AT KPIA AROUND 16Z AND KDEC-KCMI AROUND 19Z. LOW
LEVEL WIND SHEAR WILL AFFECT THE TERMINALS THE NEXT SEVERAL
HOURS DUE TO 45-50 KT WINDS AT 2000 FT AGL. SURFACE WINDS SSE
10-18 KTS WITH A FEW HIGHER GUSTS OVERNIGHT, SHIFTING TO SSW
AFTER 11Z-13Z, THEN CONTINUING TO VEER TOWARD NW WITH GUSTS
INCREASING TO 20-25 KTS THROUGH THE DAY AS THE COLD FRONT MOVES
THROUGH. WINDS DECREASING AFTER 00Z-02Z.
ILX WATCHES/WARNINGS/ADVISORIES
NONE.
KEY MESSAGES...NMA
DISCUSSION...NMA
AVIATION...37
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