731
FXUS63 KILX 230907 CCA
AFDILX
AREA FORECAST DISCUSSION...CORRECTED
NATIONAL WEATHER SERVICE LINCOLN IL
407 AM CDT SAT MAY 23 2026
KEY MESSAGES
- NO MAJOR STORM SYSTEMS ARE EXPECTED TO IMPACT THE REGION OVER
THE NEXT WEEK. AS A RESULT, THE SEVERE WEATHER RISK ACROSS
CENTRAL ILLINOIS WILL REMAIN LOW (LESS THAN A 5% CHANCE)
THROUGH NEXT FRIDAY.
DISCUSSION
ISSUED AT 304 AM CDT SAT MAY 23 2026
*** SHOWERS AND A FEW THUNDERSTORMS TONIGHT ***
A SHORT-WAVE TROUGH NOTED ON 07Z/2AM WATER VAPOR IMAGERY OVER
INDIANA WILL CONTINUE TO TRACK NORTHEASTWARD AWAY FROM CENTRAL
ILLINOIS EARLY THIS MORNING. A FEW LINGERING SHOWERS WILL BE
POSSIBLE ALONG/EAST OF THE I-57 CORRIDOR THROUGH DAYBREAK BEFORE
DRY CONDITIONS RETURN DUE TO SYNOPTIC SUBSIDENCE IN THE WAKE OF
THE DEPARTING WAVE. SKIES WILL INITIALLY BE CLOUDY THIS
MORNING, BUT WILL BECOME PARTLY SUNNY DURING THE AFTERNOON AS
HIGH TEMPERATURES TOP OUT IN THE MIDDLE TO UPPER 70S. MEANWHILE
A SECOND SHORT-WAVE CURRENTLY UPSTREAM ACROSS EASTERN COLORADO
WILL APPROACH FROM THE WEST BY LATE AFTERNOON. THE AIRMASS AHEAD
OF THIS FEATURE WILL BECOME WEAKLY UNSTABLE WITH NAM SBCAPES
REACHING 1000-1500J/KG WEST OF THE ILLINOIS RIVER AFTER 21Z/4PM.
AS OCCURRED AHEAD OF THE WAVE LAST EVENING ACROSS NEBRASKA/KANSAS,
CAMS ARE SHOWING A LINE OF BROKEN CONVECTION FORMING NEAR THE
MISSISSIPPI RIVER BY LATE AFTERNOON, THEN PUSHING EASTWARD TO
NEAR THE I-55 CORRIDOR BY MIDNIGHT. AREAL COVERAGE OF PRECIP
WILL INITIALLY REMAIN LOW DUE TO LACK OF SUFFICIENT DEEP-LAYER
MOISTURE, BUT WILL INCREASE OVERNIGHT AS A WEAK LLJ ADDS
ADDITIONAL MOISTURE. BASED ON MODEL CONSENSUS, HAVE CONFINED LOW
POPS (20-30% CHANCE) TO LOCATIONS WEST OF THE ILLINOIS RIVER
LATE THIS AFTERNOON, THEN HAVE INCREASED POPS TO 40-50%
EVERYWHERE TONIGHT. DAYTIME INSTABILITY WILL QUICKLY WANE AFTER
SUNSET: HOWEVER, ENOUGH ELEVATED INSTABILITY WILL REMAIN PRESENT
TO WARRANT ISOLATED THUNDER THROUGH THE NIGHT. SCATTERED
SHOWERS WILL BE ONGOING ALONG/EAST OF THE ILLINOIS RIVER SUNDAY
MORNING, BUT WILL COME TO AN END FROM WEST TO EAST ACROSS THE
AREA DURING THE AFTERNOON. DESPITE THE PRECIP CHANCES TONIGHT
INTO EARLY SUNDAY, RAINFALL WILL REMAIN LIGHT...GENERALLY
RANGING FROM 0.10 TO 0.25 WITH A FEW ISOLATED POCKETS IN EXCESS
OF 0.25.
*** ADDITIONAL RAIN CHANCES NEXT WEEK ***
AFTER A DRY DAY ON MONDAY, THE NBM SPREADS RAIN CHANCES BACK
INTO CENTRAL ILLINOIS FROM SOUTH TO NORTH BEGINNING AS EARLY AS
TUESDAY...THEN LINGERING THROUGH FRIDAY. THE 00Z MODELS ARE ALL
IN GOOD AGREEMENT CONCERNING THE GENERAL SYNOPTIC SET-UP NEXT
WEEK, FEATURING A POTENTIAL BLOCKING PATTERN WITH STRENGTHENING
UPPER RIDGING OVER THE UPPER MIDWEST AND A LOW OVER THE LOWER
MISSISSIPPI RIVER VALLEY. WHILE MODELS SHOW SHOWERS/THUNDER
GRADUALLY PIVOTING NORTHWARD INTO AT LEAST PARTS OF CENTRAL
ILLINOIS, THE EXACT NORTHERN EXTENT REMAINS IN QUESTION AS
NORTHERLY FLOW BETWEEN THE RIDGE AND ANOTHER SHORT-WAVE DIGGING
SOUTHWARD INTO NEW ENGLAND SHARPENS. THIS MAY TEND TO SUPPRESS
THE SOUTHERN WAVE AND FORCE ITS ASSOCIATED PRECIP BACK SOUTHWARD
AS THE WEEK PROGRESSES. FOR NOW, THE FORECAST IS SHOWERY FROM
TUESDAY THROUGH FRIDAY...BUT THIS MAY CHANGE IF CURRENT TRENDS
PERSIST. WHILE RAIN IS IN THE FORECAST NEXT WEEK, THE LACK OF A
STRONG SYSTEM AND OVERALL WEAK INSTABILITY/SHEAR WILL PREVENT
SEVERE WEATHER DEVELOPMENT THROUGHOUT THE ENTIRE FORECAST
PERIOD. AS A RESULT, THE LATEST MACHINE LEARNING ALGORITHMS
FEATURE LITTLE TO NO CHANCE (LESS THAN A 5% CHANCE) FOR SEVERE
WEATHER ACROSS CENTRAL ILLINOIS THROUGH AT LEAST NEXT FRIDAY.
AVIATION /12Z TAFS THROUGH 12Z SUNDAY/
ISSUED AT 350 AM CDT SAT MAY 23 2026
CEILINGS WILL CONTINUE TO BE THE PRIMARY FORECAST CHALLENGE
WITH THE 12Z TAF ISSUANCE AS CLOUD BASES VARY CONSIDERABLY
ACROSS CENTRAL ILLINOIS EARLY THIS MORNING. WHILE MVFR CEILINGS
PREVAIL ACROSS THE MAJORITY OF THE AREA, THE LATEST SATELLITE
IMAGERY AND LOCAL OBS INDICATE A LARGE HOLE IN THE LOW CLOUD
COVER ALONG A LINE FROM KRFD SOUTHWARD TO NEAR KAAA...INCLUDING
BOTH KPIA/KBMI. THE HRRR SEEMS TO HAVE A DECENT HANDLE ON THE
CURRENT SITUATION AND SHOWS CEILINGS LOWERING AT KBMI OVER THE
NEXT COUPLE OF HOURS, BUT PERHAPS REMAINING VFR AT KPIA.
HRRR/NAM FORECAST SOUNDINGS THEN SUGGEST CEILINGS WILL SCATTER
AND/OR DIURNALLY RISE TO LOW VFR EVERYWHERE TOWARD MIDDAY. DRY
WEATHER IS INITIALLY ANTICIPATED: HOWEVER, AN APPROACHING TROUGH
WILL TRIGGER ISOLATED SHOWERS/THUNDER WEST OF THE ILLINOIS RIVER
BY LATE AFTERNOON. BASED ON THE 06Z HRRR, HAVE INCLUDED VCSH AT
KPIA AFTER 22Z ACCORDINGLY. ALL MODELS INCREASE THE AREAL
COVERAGE OF PRECIP FURTHER EAST AFTER DARK, SO HAVE ADDED A
TEMPO GROUP FOR SHOWERS AND A RETURN TO MVFR CEILINGS AT ALL
TERMINALS EXCEPT KPIA BETWEEN 08Z AND 12Z. WINDS WILL REMAIN
LIGHT AND VARIABLE THROUGH THE ENTIRE PERIOD.
ILX WATCHES/WARNINGS/ADVISORIES
NONE.
KEY MESSAGES...BARNES
DISCUSSION...BARNES
AVIATION...BARNES
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