096
FXUS63 KILX 231919
AFDILX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE LINCOLN IL
219 PM CDT WED APR 23 2025
KEY MESSAGES
- ABOVE NORMAL TEMPERATURES WILL PREVAIL THROUGH THE REMAINDER OF
THE WEEK. EXPECT AFTERNOON HIGHS AROUND 80 DEGREES AGAIN
THURSDAY AND MID TO UPPER 70S FRIDAY.
- A COLD FRONT WILL SWEEP ACROSS CENTRAL ILLINOIS EARLY NEXT WEEK.
THERE IS A RISK FOR SEVERE THUNDERSTORMS (15% WITHIN 25 MILES)
TUESDAY.
DISCUSSION
ISSUED AT 214 PM CDT WED APR 23 2025
THIS AFTERNOON, HIGH PRESSURE IS IN PLACE FROM HUDSON BAY TO THE
EASTERN GREAT LAKES, WITH RIDGING EXTENDING BACK ACROSS THE MID
MISSISSIPPI VALLEY. SOUTH TO SOUTHWEST FLOW IS IN PLACE ACROSS
CENTRAL ILLINOIS ALLOWING FOR TEMPS TO RUN WELL ABOVE NORMAL WITH
HIGHS AROUND 80 DEGREES TODAY AND AGAIN THURSDAY. MEANWHILE, TO
OUR NORTHWEST, A WEAKENING, BROAD FRONTAL ZONE EXTENDS FROM THE
MID MISSOURI VALLEY INTO SOUTHERN WISCONSIN AND WILL BE THE FOCUS
FOR ANY SHOWERS AND STORMS TODAY AND AGAIN THURSDAY, BUT SHOULD
STAY OUT OF THE ILX FORECAST AREA.
A SERIES OF SHORTWAVE TROUGHS WILL MOVE ACROSS THE REGION LATE IN
THE WEEK BRINGING A CHANCE FOR SHOWERS AND A FEW STORMS BACK TO
THE AREA. THE FIRST PAIR OF WAVES IS EXPECTED TO MOVE ACROSS
SOUTHERN ILLINOIS THURSDAY EVENING AND IA/NORTHERN IL FRIDAY
NIGHT. THE SOUTHERN WAVE WILL ENCOUNTER SOME DRY AIR AND POOR MID
LEVEL LAPSE RATES WHICH MAY CAUSE CONVECTION TO STRUGGLE, BUT
STILL SUFFICIENT FOR SCATTERED SHOWERS AND A FEW STORMS. BETTER
COVERAGE OF PRECIP WILL APPROACH FROM THE NORTHWEST THURSDAY NIGHT
AS THE NORTHERN WAVE MOVES ALONG THE AFOREMENTIONED SURFACE
FRONTAL ZONE. THE BETTER FORCING WILL HELP TO COMPENSATE FOR THE
LACK OF ANY NOTABLE INSTABILITY. THE THIRD WAVE IS PROGGED TO MOVE
ACROSS CENTRAL ILLINOIS FRIDAY AFTERNOON AND WILL HELP PUSH THE
SURFACE FRONT ACROSS CENTRAL ILLINOIS. THERE REMAINS SOME
UNCERTAINTY ON HOW MUCH RECOVERY THERE WILL BE BEHIND THE INITIAL
WAVES BUT AT LEAST MODEST INSTABILITY IS EXPECTED TO DEVELOP
FRIDAY AFTERNOON. GFS ADVERTISES AROUND 500 J/KG MLCAPE BUT DEEP
LAYER SHEAR IS ALSO WEEK, 20-25 KT, WHICH WILL KEEP A SEVERE
WEATHER THREAT FROM MATERIALIZING. NBM MEAN 48-HOUR QPF GENERALLY
RUNS AROUND HALF AN INCH ACROSS CENTRAL ILLINOIS THROUGH SATURDAY
MORNING. 95TH PERCENTILE DOES INCREASES TO 1.25-1.50 INCHES BUT
THESE HIGHER END AMOUNTS WILL BE LOCALIZED UNDER THE STRONGER
SHOWERS/STORMS.
THIS WEEKEND, HIGH PRESSURE WILL MOVE EAST ACROSS THE GREAT LAKES
WHILE ALOFT, AN UPPER LEVEL RIDGE WILL GRADUALLY AMPLIFY AS IT
MOVES FROM THE GREAT PLAINS TO THE MISSISSIPPI VALLEY. TEMPS WILL
BOTTOM OUT SATURDAY IN NORTHEAST FLOW KEEPING HIGHS IN THE 60S. AS
FLOW TURNS SOUTHERLY BEHIND THE RIDGE AXIS AND UNDER THE BUILDING
UPPER RIDGE, TEMPS WILL WARM BACK INTO THE 70S SUNDAY AND 80S
MONDAY.
MODELS CONTINUE TO ADVERTISE A DEEP LOW LIFTING ACROSS THE UPPER
MIDWEST LATE MONDAY INTO QUEBEC TUESDAY AS A TRAILING COLD FRONT
PUSHES ACROSS CENTRAL ILLINOIS. LREF JOINT PROBABILITIES FOR
SBCAPE GREATER THAN 500 J/KG AND BULK SHEAR GREATER THAN 30 KT RUN
AROUND 50-60 PERCENT ACROSS THE WESTERN PARTS OF THE STATE MONDAY
AND SHIFT TO SOUTHERN/EASTERN ILLINOIS TUESDAY INDICATING THE
POTENTIAL FOR SEVERE WEATHER IN THE AREA.
DEUBELBEISS
AVIATION
(FOR THE 18Z TAFS THROUGH 18Z THURSDAY AFTERNOON)
ISSUED AT 1208 PM CDT WED APR 23 2025
RIDGE OF HIGH PRESSURE WILL REMAIN LOCATED JUST SOUTHEAST OF THE
TERMINALS THROUGH THE PERIOD ALLOWING WINDS TO REMAIN LIGHT, LESS
THAN 10 KT. BECAUSE OF THE LOW MAGNITUDE, THERE MAY BE SOME
VARIABILITY AT TIMES, BUT SHOULD GENERALLY FAVOR A S/SE DIRECTION.
VFR CONDITIONS ARE EXPECTED THROUGH THE PERIOD.
DEUBELBEISS
ILX WATCHES/WARNINGS/ADVISORIES
NONE.
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