445
FXUS63 KILX 300902
AFDILX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE LINCOLN IL
402 AM CDT SUN MAR 30 2025
KEY MESSAGES
- TWO ROUNDS OF CONVECTION ARE ANTICIPATED TODAY. THE FIRST WILL
MAINLY IMPACT LOCATIONS ALONG AND WEST OF I-55 THIS MORNING.
GUSTY WINDS AND HAIL WILL BE POSSIBLE WITH A FEW OF THE CELLS.
- THE SECOND ROUND OF CONVECTION WILL DEVELOP JUST EAST OF THE
I-55 CORRIDOR TOWARD MIDDAY...THEN WILL QUICKLY TRACK EASTWARD
INTO INDIANA BY EARLY EVENING. DAMAGING WIND GUSTS, VERY LARGE
HAIL, AND A FEW TORNADOES ARE LIKELY WITH THESE CELLS.
- ANOTHER SYSTEM WILL BRING A CHANCE FOR STRONG TO SEVERE
THUNDERSTORMS ON WEDNESDAY: HOWEVER, IT IS STILL TOO EARLY TO
PINPOINT EXACT DETAILS.
SHORT TERM
(TODAY THROUGH MONDAY)
ISSUED AT 402 AM CDT SUN MAR 30 2025
A LINE OF THUNDERSTORMS SEEN ON 0830Z/330AM RADAR IMAGERY ACROSS
WESTERN MISSOURI/ARKANSAS WILL LIFT NORTHEASTWARD OVER THE NEXT
SEVERAL HOURS. BASED ON RADAR TIMING TOOLS AND THE LATEST HRRR
OUTPUT, THE STORMS WILL REACH THE FAR SW KILX CWA AROUND
WINCHESTER AND JACKSONVILLE BETWEEN 7AM AND 8AM, THEN WILL PUSH
NORTH OF THE I-74 CORRIDOR AFTER 10AM. WHILE WIDESPREAD SEVERE
WEATHER IS NOT EXPECTED WITH THIS INITIAL ROUND OF CONVECTION,
MUCAPE VALUES INCREASING INTO THE 1000-1500J/KG AND MODESTLY STEEP
MID-LEVEL LAPSE RATES WILL SUPPORT THE POTENTIAL FOR GUSTY WINDS
AND MARGINALLY SEVERE HAIL. GIVEN THE CURRENT TRAJECTORY, THINK
THE STORMS WILL PRIMARILY IMPACT LOCATIONS ALONG/WEST OF I-55 THIS
MORNING.
ONCE THE MORNING ACTIVITY DEPARTS, A SECOND MORE SIGNIFICANT ROUND
OF CONVECTION WILL DEVELOP ALONG/AHEAD OF THE ADVANCING COLD
FRONT/OUTFLOW BOUNDARY. WHILE 00Z CAMS STILL OFFER VARYING
SOLUTIONS AS TO THE EXACT LOCATION OF CONVECTIVE INITIATION,
CONSENSUS CONTINUES TO POINT TO LOCATIONS JUST EAST OF THE I-55
CORRIDOR BETWEEN 12PM AND 2PM. THE PRE-FRONTAL AIRMASS WILL BECOME
MODERATELY UNSTABLE AND HIGHLY SHEARED...WITH SBCAPES OF
1500-2000J/KG AND 0-6KM SHEAR OF 50-55KT. GIVEN AMPLE INSTABILITY,
STEEP MID-LEVEL LAPSE RATES, AND A FREEZING LEVEL OF 10,000FT OR
LESS...VERY LARGE HAIL WILL BE A PRIMARY CONCERN WITH THE CELLS AS
THEY FIRST BEGIN TO DEVELOP. AS SUCH, SPC IS INDICATING A GREATER
THAN 10% CHANCE FOR HAIL LARGER THAN 2 INCHES IN DIAMETER EVERYWHERE
EAST OF I-55. WITH A MID-LEVEL JET STREAK SHIFTING ACROSS THE
REGION, SPEED SHEAR WILL INCREASE MARKEDLY THIS AFTERNOON,
RESULTING IN IMPRESSIVE 0-3KM VGP VALUES IN EXCESS OF 0.5. GIVEN
THE HIGH DEGREE OF SHEAR, HREF ENSEMBLE MEAN SIGNIFICANT TORNADO
PARAMETER (STP) VALUES CLIMB ABOVE 2 ALONG/SOUTH OF A SHELBYVILLE
TO DANVILLE LINE. AM THEREFORE CONCERNED ABOUT A FEW POTENTIALLY
STRONG TORNADOES WITH THE DEVELOPING SUPERCELLS. GIVEN DEEP-LAYER
SHEAR VECTORS PARALLEL WITH THE BOUNDARY, THINK THE CELLS WILL
QUICKLY GROW UPSCALE INTO A QLCS...WITH AN ATTENDANT DAMAGING WIND
GUST AND TORNADO RISK AS THE LINE RACES EASTWARD ACROSS THE I-57
CORRIDOR AND INTO INDIANA BY EARLY EVENING.
ONCE THE COLD FRONT PASSES, THE SEVERE WEATHER RISK WILL COME TO
AN END AND A MUCH COOLER AIRMASS WILL ARRIVE TONIGHT INTO MONDAY.
AFTER HIGHS IN THE UPPER 60S AND LOWER 70S TODAY, READINGS WILL
ONLY REACH THE UPPER 40S AND LOWER 50S ON MONDAY. AS HIGH PRESSURE
BUILDS INTO THE REGION AND WINDS DIMINISH, RADIATIONAL COOLING
WILL ALLOW LOW TEMPERATURES MONDAY NIGHT TO DIP INTO THE UPPER 20S
AND LOWER 30S.
BARNES
LONG TERM
(TUESDAY THROUGH SATURDAY)
ISSUED AT 402 AM CDT SUN MAR 30 2025
AFTER THAT, THE ACTIVE WEATHER PATTERN WILL CONTINUE THROUGH THE
REMAINDER OF THE WEEK. DRY CONDITIONS WILL PREVAIL INTO TUESDAY
BEFORE YET ANOTHER STRONG STORM SYSTEM APPROACHES FROM THE
SOUTHWEST TUESDAY NIGHT INTO WEDNESDAY. WHILE IT IS STILL TOO
EARLY TO PROPERLY ASSESS ANY ATTENDANT SEVERE WEATHER RISK, SPC IS
HIGHLIGHTING MUCH OF CENTRAL ILLINOIS WITH A 15% PROBABILITY OF
SEVERE AND A 30% CHANCE FOR LOCATIONS ALONG/SOUTH OF I-70. ONCE
THE SYSTEM PASSES, THE MAIN BAROCLINIC ZONE WILL DROP SOUTHWARD
AND STALL ACROSS THE OHIO RIVER VALLEY AS IT BECOMES PARALLEL WITH
THE DEEP-LAYER SOUTHWESTERLY FLOW PATTERN DEVELOPING ACROSS THE
CENTRAL/EASTERN U.S. AS A SERIES OF WAVES INTERACTS WITH THE
BOUNDARY, ADDITIONAL ROUNDS OF SHOWERS/STORMS WILL BE POSSIBLE BY
THE END OF THE WEEK. THE END RESULT WILL BE A WET AND UNSETTLED
EXTENDED FORECAST.
BARNES
AVIATION
(FOR THE 06Z TAFS THROUGH 06Z SUNDAY NIGHT)
ISSUED AT 1208 AM CDT SUN MAR 30 2025
CHALLENGING AVIATION FORECAST OVER THE NEXT 24 HOURS WITH NUMEROUS
CATEGORY CHANGES AND SCATTERED CONVECTION, ALL LEADING TO LOWER
FORECAST CONFIDENCE ON THE FINE DETAILS. CURRENTLY IFR CEILINGS
COVER MUCH OF CENTRAL IL, THOUGH JUST WEST OF KPIA-KSPI THE LOW
CEILINGS CLEAR OUT. WITH FLOW IN THE CLOUD BEARING LAYER FROM THE
SOUTH, FEEL THESE SITES WILL BE ON THE EDGE OF IFR CEILINGS
THROUGH SUNRISE. THEN ALL SITES SHOULD RISE TO MVFR DURING THE
MORNING. NEXT ISSUE IS TSRA DEVELOPMENT BETWEEN 17-21Z. HIGH
RESOLUTION MODELS FAVOR INITIATION NEAR THE I-55 CORRIDOR, THEN
TRACK STORMS EAST THROUGH MID AFTERNOON. SO HIGHER CONFIDENCE THAT
TSRA WILL AFFECT KDEC- KCMI AND LOWER CONFIDENCE FARTHER WEST.
STRONG WIND GUSTS AND IFR VISIBILITY WILL BE COMMON WITH THE
STORMS. AFTER THE STORMS CLEAR, A PERIOD OF VFR CONDITIONS IS
LIKELY AT KCMI- KDEC, WHILE SITES FARTHER NORTHWEST WILL STAY
PRIMARILY MVFR. BUT THE MVFR CEILINGS SHOULD EVENTUALLY SPREAD
BACK SOUTHEAST DURING THE EVENING. GUSTY SOUTH-SOUTHWEST WINDS TO
PREVAIL AHEAD OF A COLD FRONT, VEERING WEST-SOUTHWEST BEHIND THE
FRONT, AND WEST- NORTHWEST DURING THE EVENING. GUSTS AROUND 25 KT
WILL BE COMMON THROUGH THE FORECAST.
25
ILX WATCHES/WARNINGS/ADVISORIES
NONE.
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