418
FXUS63 KILX 230508
AFDILX
AREA FORECAST DISCUSSION...UPDATED AVIATION
NATIONAL WEATHER SERVICE LINCOLN IL
1208 AM CDT WED APR 23 2025
KEY MESSAGES
- ABOVE NORMAL TEMPERATURES WILL PREVAIL THROUGH THE REMAINDER OF
THE WEEK. EXPECT AFTERNOON HIGHS AROUND 80 DEGREES WEDNESDAY AND
THURSDAY.
UPDATE
ISSUED AT 938 PM CDT TUE APR 22 2025
SURFACE ANALYSIS LATE THIS EVENING SHOWS A FRONTAL BOUNDARY DRAPED
FROM NORTHERN ILLINOIS INTO CENTRAL IOWA. SEVERAL STORMS DEVELOPED
SOUTH OF THE BOUNDARY IN NORTH-CENTRAL ILLINOIS THIS EVENING, WITH
ACTIVITY STILL ONGOING NORTH OF A BLOOMINGTON TO GIBSON CITY LINE.
BITS OF SHORTWAVE ENERGY TRAVERSING THROUGH MID-LEVEL ZONAL FLOW AND
SOME LINGERING SURFACE BOUNDARIES HAVE SERVED AS THE SOURCE OF LIFT
FOR CONTINUED STORM PERSISTENCE. THE LATEST SPC MESOANALYSIS
SHOWS LESS THAN 500 J/KG OF MLCAPE OVER CENTRAL PARTS OF THE STATE
AND EFFECTIVE SHEAR OF AROUND 25-30 KTS. WITH THE LOSS OF DAYTIME
HEATING AND STORMS MOVING INTO A LESS FAVORABLE ENVIRONMENT ,
ACTIVITY SHOULD BEGIN TO WANE OVER THE NEXT HOUR OR SO. ANOTHER
PUSH OF SHOWERS AND STORMS LOOKS TO IMPACT ESSENTIALLY THE SAME
AREA LATER TONIGHT AS ANOTHER UPPER SHORTWAVE SWINGS THROUGH THE
AREA. THE LATEST RUN OF CAMS SHOWS IT ARRIVING SOMETIME AFTER 2 AM
AND CONTAINING THROUGH ABOUT SUNRISE, POSING A THREAT FOR POCKETS
OF HEAVY RAIN, GUSTY WINDS, AND SMALL HAIL.
NMA
DISCUSSION
ISSUED AT 228 PM CDT TUE APR 22 2025
THIS AFTERNOON, A BROAD FRONTAL ZONE LIES FROM SOUTHEASTERN
WISCONSIN BACK ACROSS NORTHERN ILLINOIS AND INTO WEST CENTRAL
ILLINOIS. NEAR THE FRONT, TEMPS IN THE LOWER TO MID 70S AND DEW
POINTS POOLING IN THE MID 50S ARE CONTRIBUTING TO MLCAPE OF 1000-
1250 J/KG WITH LITTLE CONVECTIVE INHIBITION. SCATTERED SHOWERS AND
STORMS ARE EXPECTED TO CONTINUE TO PERCOLATE WITHIN THE FRONTAL
TROUGH THROUGH LATE THIS EVENING. A FEW OF THE STRONGER STORMS
COULD BECOME SEVERE WITH DAMAGING WIND GUSTS AND ONE INCH HAIL THE
PRIMARY CONCERNS.
QUASI-STATIONARY FRONTAL BOUNDARY WILL GRADUALLY BEGIN TO LIFT
BACK NORTH WEDNESDAY TO NEAR THE IL/WI STATE LINE AND WILL SERVE
AS THE FOCUS FOR ADDITIONAL SHOWERS AND STORMS. WEAK INSTABILITY
NEAR THE FRONT WILL TAPER OFF TO LESS THAN 100 J/KG BY THE I-74
CORRIDOR. LACK OF INSTABILITY FURTHER SOUTH AND WELL DISPLACED
FROM THE FORCING, CENTRAL ILLINOIS SHOULD BE DRY THROUGH THE
AFTERNOON AND EVENING. TEMPERATURES WILL WARM TO AROUND 80 DEGREES
AREA-WIDE WEDNESDAY AFTERNOON.
CONDITIONS THURSDAY WILL BE SIMILAR TO WEDNESDAY WITH A DRY START
TO THE DAY AND TEMPERATURES WARMING TO AROUND 80 DEGREES. A
SHORTWAVE TROUGH LIFTING FROM THE CENTRAL PLAINS WILL CROSS THE
MID MISSISSIPPI VALLEY THURSDAY EVENING WITH ACCOMPANYING SHOWERS
AND STORMS APPROACHING FROM THE WEST. ANY CONVECTION WILL BE
OUTRUNNING THE STRONGER INSTABILITY TO OUR WEST SO SHOULD BE IN A
WEAKENING PHASE WITH A SEVERE THREAT NOT APPARENT.
MORE WIDESPREAD SHOWERS AND STORMS ARE EXPECTED FRIDAY AS SYNOPTIC
SCALE FORCING INCREASES ACROSS THE REGION. ALOFT, COUPLED JET
STREAKS WILL BE IN PLACE WITH THE NORTHERN STREAM OVER THE GREAT
LAKES AND THE SOUTHERN STREAM OVER THE SOUTHERN PLAINS. THE RIGHT
ENTRANCE REGION OF THE FORMER AND THE LEFT EXIT REGION OF THE
LATTER WILL BE LOCATED OVER THE MID MISSISSIPPI VALLEY AND MIDWEST
FRIDAY. IN ADDITION, ANOTHER SHORTWAVE TROUGH WILL DIG ACROSS THE
MID MISSISSIPPI VALLEY EARLY FRIDAY EVENING. WEAK INSTABILITY
WITH MLCAPE GENERALLY LESS THAN 500 J/KG AND SUBOPTIMAL DEEP LAYER
SHEAR OF 20-25KT WILL LIMIT ANY SEVERE THREAT WITH CONVECTION
FRIDAY AFTERNOON AND EVENING.
BEHIND FRIDAY'S DEPARTING WAVE, HIGH PRESSURE WILL BUILD SOUTH
FROM THE CANADIAN PRAIRIES ACROSS THE MIDWEST OVER THE WEEKEND.
TEMPS BRIEFLY MODERATE SATURDAY WITH HIGHS BACK DOWN IN THE MID TO
UPPER 60S IN THE NORTHERLY FLOW. RIDGE AXIS SHIFTS TO OUR EAST
SUNDAY ALLOWING TEMPS TO REBOUND BACK INTO THE 70S ON THE RETURN
OF SOUTHERLY FLOW. EXPECT THE WEEKEND TO BE DRY UNDER THE
INFLUENCE OF THE RIDGE.
MORE ACTIVE WEATHER RETURNS EARLY NEXT WEEK THOUGH DETAILS REMAIN
A BIT UNSURE AT THIS DISTANCE DUE TO DIFFERENCES IN THE STRENGTH
AND TIMING OF LOW PRESSURE LIFTING ACROSS THE UPPER MIDWEST. A
TRAILING COLD FRONT WILL EVENTUALLY PASS THROUGH CENTRAL ILLINOIS.
IF DIURNAL TIMING IS FAVORABLE WITH PASSAGE OF THIS SYSTEM, AND
GIVEN THE MAGNITUDE OF THE LOW AND FAVORABLE LOW LEVEL
TRAJECTORIES ALLOWING A RETURN OF GULF MOISTURE INTO THE REGION,
WOULDN'T RULE OUT A SEVERE WEATHER THREAT. NBM JOINT PROBABILITIES
FOR SBCAPE GREATER THAN 500 J/KG AND 30 KTS OF BULK SHEAR PEAK
AROUND 60 PERCENT FOR WESTERN PORTIONS OF THE AREA MONDAY EVENING
AND AGAIN AREA-WIDE TUESDAY AFTERNOON. TIMING DETAILS WILL HAVE TO
BE IRONED OUT IN THE UPCOMING DAYS AS THIS SYSTEM COMES INTO
BETTER FOCUS.
DEUBELBEISS
AVIATION
(FOR THE 06Z TAFS THROUGH 06Z WEDNESDAY NIGHT)
ISSUED AT 1208 AM CDT WED APR 23 2025
WEST-EAST BAND OF CONVECTION OVER SOUTHEAST IOWA CONTINUES TO
TRACK EASTWARD, AND THERE REMAINS SOME CONCERN THAT THIS WOULD
REACH KPIA IN A FEW HOURS. THERE IS ENOUGH UNCERTAINTY AT THE
MOMENT AT THIS PROSPECT TO KEEP THE MENTION TO PROB30 FOR THUNDER,
AND WILL EVALUATE OVER THE NEXT COUPLE OF HOURS FOR ANY AMENDMENTS
TO HIT IT HARDER.
IN GENERAL, VFR CONDITIONS TO PREVAIL OVER CENTRAL ILLINOIS THE
NEXT 24 HOURS, WITH SOUTH WINDS INCREASING TO NEAR 10 KNOTS BY
LATE MORNING.
GEELHART
ILX WATCHES/WARNINGS/ADVISORIES
NONE.
CLICK HERE TO GO TO PREVIOUS BULLETINS.
Main Text Page