021
FXUS63 KILX 291941
AFDILX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE LINCOLN IL
241 PM CDT SUN MAR 29 2026
KEY MESSAGES
- UNSETTLED WEATHER IS ON TAP FOR MUCH OF THE WEEK. THERE IS A
60-80% CHANCE OF GREATER THAN 2 INCHES OF RAIN FROM TUESDAY
THROUGH NEXT SATURDAY.
- THE GREATEST PROBABILITY FOR SEVERE WEATHER WILL FOCUS TUESDAY
AFTERNOON AND EVENING WHEN A COLD FRONT PUSHES INTO THE
REGION.
DISCUSSION
ISSUED AT 241 PM CDT SUN MAR 29 2026
..SEVERE WEATHER RISK ON TUESDAY
AS HAS BEEN NOTED BY THE PAST SEVERAL MODEL RUNS, THE 12Z MAR 29
SUITE CONTINUES TO SHOW A COLD FRONT DROPPING INTO ILLINOIS LATE
TUESDAY. WHILE THE EXACT PLACEMENT OF THE BOUNDARY BY PEAK
HEATING IS STILL IN QUESTION, THE GENERAL CONSENSUS SUGGESTS IT
WILL BE APPROACHING THE ILLINOIS RIVER VALLEY BY MIDDAY AND I-55
TOWARD SUNSET. MOISTURE RETURN AHEAD OF THE FRONT WILL BE
SOMEWHAT LACKING WITH NAM/GFS SHOWING DEWPOINTS MOSTLY IN THE
MIDDLE TO UPPER 50S...WHICH TRANSLATES TO SBCAPES OF
1000-1500J/KG. IN ADDITION, DEEP-LAYER SHEAR APPEARS TO BE
WEAKER THAN IN RECENT SEVERE WEATHER EVENTS AS THE PRIMARY UPPER
FORCING SLIDES ACROSS THE NORTHERN TIER OF STATES INTO THE
GREAT LAKES WELL NORTH OF ILLINOIS. NAM GENERALLY INDICATES
0-6KM BULK SHEAR IN THE 35-45KT RANGE AHEAD OF THE FRONT. WHILE
THE INSTABILITY/SHEAR PROFILE IS CERTAINLY NOT OFF THE CHARTS,
THE PRESENCE OF A FORCING MECHANISM COMING INTO THE ENVIRONMENT
BY PEAK HEATING WILL BE SUFFICIENT TO TRIGGER STRONG TO SEVERE
THUNDERSTORMS TUESDAY AFTERNOON AND EVENING. AS A RESULT, BOTH
NCAR AND NSSL MACHINE LEARNING ALGORITHMS INDICATE A GREATER
THAN 30% CHANCE FOR SEVERE, WHILE COLORADO STATE SHOWS A 15-30%
CHANCE. AN EARLY ASSESSMENT HIGHLIGHTS THE PRIMARY RISKS AS
DAMAGING WIND GUSTS AND MARGINALLY SEVERE HAIL.
..UNSETTLED WEATHER THROUGH THE REMAINDER OF THE WEEK
ONE CHANGE THE MOST RECENT MODELS DEPICT IS STALLING THE TUESDAY
NIGHT FRONTAL BOUNDARY FURTHER NORTH THAN ORIGINALLY THOUGHT.
INSTEAD OF SINKING INTO THE OHIO RIVER VALLEY ON WEDNESDAY,
GENERAL CONSENSUS NOW SUGGESTS THE BOUNDARY WILL REMAIN HUNG-UP
ACROSS CENTRAL ILLINOIS, WHICH WILL KEEP RAIN CHANCES ALIVE
THROUGH WEDNESDAY. AS A SHORT-WAVE TROUGH EJECTING EASTWARD OUT
OF THE PLAINS INTERACTS WITH THE BOUNDARY, A WAVE OF LOW
PRESSURE IS EXPECTED TO DEVELOP AND TRACK NORTHEASTWARD INTO
INDIANA BY FRIDAY MORNING. THIS WILL BRING ANOTHER WAVE OF
WIDESPREAD SHOWERS AND A FEW THUNDERSTORMS THURSDAY/THURSDAY
NIGHT. AFTER A BRIEF LULL IN THE ACTION ON FRIDAY, YET ANOTHER
WAVE AND ITS ASSOCIATED COLD FRONT WILL ARRIVE LATE FRIDAY NIGHT
INTO SATURDAY. CONFIDENCE CONTINUES TO GROW THAT BENEFICIAL
RAINFALL WILL FURTHER ALLEVIATE THE LONG-TERM DROUGHT CONDITIONS
ACROSS CENTRAL ILLINOIS THIS WEEK. THE LATEST LREF HIGHLIGHTS A
60-80% CHANCE OF GREATER THAN 2 INCHES OF RAIN ACROSS THE ENTIRE
AREA...WITH A 30-40% CHANCE OF MORE THAN 3 INCHES SOUTH OF A
MACOMB TO PONTIAC LINE AND NORTH OF I-70.
..STRONG THUNDERSTORM POTENTIAL NEXT SATURDAY
WHILE IT IS STILL TOO EARLY TO PINPOINT ANY SPECIFIC SEVERE
WEATHER RISK, THE FINAL SYSTEM OF THE ACTIVE WEEK AHEAD BEARS
WATCHING FOR NEXT SATURDAY. ALL MODELS AGREE THAT A DIGGING
UPPER TROUGH WILL PUSH A STRONG COLD FRONT THROUGH CENTRAL
ILLINOIS SOMETIME FROM FRIDAY NIGHT THROUGH SATURDAY NIGHT. THE
ECMWF IN PARTICULAR HAS LOOKED RATHER OMINOUS OVER THE PAST FEW
RUNS, FEATURING A DEEPENING LOW TRACKING FROM IOWA TO MICHIGAN
AND A TRAILING COLD FRONT PASSING THROUGH CENTRAL ILLINOIS
SATURDAY AFTERNOON. WHILE MACHINE LEARNING ALGORITHMS DO NOT YET
HAVE A CLEAR SIGNAL FOR SEVERE, BOTH NCAR AND NSSL INDICATE AT
LEAST A LOW PROBABILITY. ONCE THE FRONT PASSES, COOLER/DRIER
CONDITIONS WILL SETTLE BACK INTO THE MIDWEST BY EARLY NEXT WEEK.
AVIATION /18Z TAFS THROUGH 18Z MONDAY/
ISSUED AT 1242 PM CDT SUN MAR 29 2026
VFR CONDITIONS WILL PREVAIL THROUGH THE ENTIRE 18Z TAF PERIOD.
AN AREA OF CLOUDS AT AROUND 5000FT WILL SPREAD EASTWARD TO THE
I-57 CORRIDOR BY 19Z...WITH OVERCAST CONDITIONS EXPECTED ACROSS
THE BOARD FOR THE REMAINDER OF THE AFTERNOON. WHILE THESE CLOUDS
MAY TEND TO THIN AT TIMES THIS EVENING AND OVERNIGHT, THEY WILL
NOT COMPLETELY CLEAR THE TERMINALS UNTIL MID-MORNING MONDAY.
WINDS WILL INITIALLY BE S WITH GUSTS TO AROUND 20KT THIS
AFTERNOON, THEN WILL DECREASE INTO THE 10-15KT RANGE BY SUNSET.
MODELS INDICATE A STRENGTHENING LOW-LEVEL JET AFTER DARK, SO
HAVE INCLUDED 40-50KT OF WIND SHEAR AT ALL SITES AFTER 03Z
ACCORDINGLY. SOME OF THIS HIGHER MOMENTUM AIR WILL MIX TO THE
SURFACE MONDAY MORNING, RESULTING IN SW WIND GUSTS OF 20-25KT AT
THAT TIME.
ILX WATCHES/WARNINGS/ADVISORIES
NONE.
KEY MESSAGES...BARNES
DISCUSSION...BARNES
AVIATION...BARNES
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