000
FXUS63 KILX 221455
AFDILX
AREA FORECAST DISCUSSION...UPDATED
NATIONAL WEATHER SERVICE LINCOLN IL
955 AM CDT SUN MAR 22 2026
KEY MESSAGES
- UNSEASONABLY WARM TEMPERATURES CONTINUE FOR MOST OF CENTRAL IL
AND ALL OF SOUTHEASTERN IL TODAY, WITH HIGHS IN THE 70S TO UPPER
80S TODAY. TEMPERATURES TURN COOLER FOR THE START OF THE WORK
WEEK, WITH HIGHS IN THE LOW TO MID 50S TOMORROW.
- GUSTY (30-40 MPH) NORTH WINDS WILL USHER A SEASONABLY COOL
AIRMASS INTO THE REGION LATE TODAY, WITH LOWS IN THE LOW-MID
30S BY MONDAY MORNING. TEMPERATURES WILL THEN SLOWLY REBOUND,
WITH A 30-50% CHANCE FOR HIGHS IN THE 80S AGAIN BY THURSDAY.
- AHEAD OF THE COLD FRONT THIS EVENING, AREAS NEAR AND SOUTH OF
I-70 HAVE A 50-70% CHANCE FOR SEEING THUNDERSTORMS. THERE IS A
LEVEL 1 OF 5 (MARGINAL) RISK FOR DAMAGING WINDS AND LARGE HAIL
WITH THOSE STORMS.
- ANOTHER CHANCE (30-50%) FOR SHOWERS AND STORMS WILL ACCOMPANY A
COLD FRONT SOMETIME WEDNESDAY INTO FRIDAY. CONFIDENCE IS LOW IN
WHETHER A SEVERE RISK OR HYDRO RISK WILL MATERIALIZE.
UPDATE
ISSUED AT 955 AM CDT SUN MAR 22 2026
A SMALL UPDATE WAS MADE TO EXTEND SLIGHT CHANCES FOR
THUNDERSTORMS SLIGHTLY FARTHER NORTHWEST, AS FAR AS SPRINGFIELD
AROUND 7 PM AS VARIOUS RECENT HIGH-RES MODELS HAVE SHIFTED STORM
ACTIVITY SLIGHTLY NORTHWEST. OTHERWISE, FORECAST REMAINS LARGELY
ON TRACK AS THE COLD FRONT THAT SHOULD ORGANIZE THUNDERSTORM
ACTIVITY THIS EVENING IS AROUND MACOMB TO PEORIA AS OF 9 AM,
STEADILY WORKING ITS WAY TOWARD I-70 BY AROUND 5 PM. THIS IS
AROUND THE TIME MODELS SUGGEST CONVECTIVE INITIATION AS A STRONG
LOW-LEVEL CAPPING INVERSION IS OVERCOME. SOUTH OF THE FRONT,
1500-2000 SBCAPE IS EXPECTED, WITH 40-50 KT BULK SHEAR. SUPERCELL
CHARACTERISTICS APPEAR POSSIBLE WITH THE EARLIEST CELLS. DESPITE
HIGH LCLS AND MODERATE STORM-RELATIVE HELICITY AROUND 150, A
TORNADO OR TWO APPEAR POSSIBLE GIVEN THE SUPERCELL CHARACTER, AND
SPC HAS ADDED A 2 PERCENT THREAT FOR TORNADOES SOUTH OF I-70.
LARGE HAIL, GOLFBALL SIZE OR LARGER WOULD BE POSSIBLE WITH ANY
SUPERCELLS AS WELL. NORTH OF THE FRONT, SCATTERED THUNDERSTORM
ACTIVITY WILL BE POSSIBLE FOR A COUPLE OF HOURS, ALTHOUGH THE
THREAT TRANSITIONS TO MORE OF A MARGINAL HAIL RISK SIX TO 10 PM
CONTINUES TO BE THE MAIN TIME FOR A SEVERE WEATHER THREAT.
37
DISCUSSION
ISSUED AT 214 AM CDT SUN MAR 22 2026
TODAY A PATTERN CHANGE WILL OCCUR. THE COLD FRONT THAT WILL MOVE
THROUGH THE FORECAST AREA TODAY IS CURRENTLY LOCATED ACROSS CENTRAL
IOWA. DAYTIME TEMPERATURES WILL DROP BY 30 DEGREES BY TOMORROW.
STRONG (POSSIBLY SEVERE) STORMS ARE POSSIBLE ACROSS SOUTHEASTERN IL
THIS EVENING. STRONG GRADIENT WINDS OUT OF THE SOUTH WILL PICK UP
THIS MORNING, BRIEFLY RELAXING AS THE FRONT PASSES, THEN PICKING
BACK UP OUT OF THE NORTH BEHIND IT.
HIGHS TODAY WILL DEPEND ON THE TIMING OF THE COLD FRONT THIS
MORNING/AFTERNOON. THE DAYTIME TEMPERATURES HAVE BEEN OVERACHIEVING
THE LAST FEW DAYS, SO HIGHS WERE BUMPED UP A FEW DEGREES WITH THIS
FORECAST PACKAGE TO ENCOMPASS THE WARMER TEMPERATURES WHERE THE COLD
FRONT WILL ARRIVE LATER IN THE DAY. THERE IS A 20+ DEGREE SPREAD
FROM NW TO SE ACROSS THE CWA. GALESBURG HAS A FORECAST HIGH OF 64
DEGREES AND LAWRENCEVILLE HAS A FORECAST HIGH OF 86 DEGREES.
SOUTHERLY WINDS WILL BEGIN TO GUST TO 25-35 KNOTS BY LATE MORNING
NORTH OF I-72, WITH THE STRONG GUSTS EXPANDING SOUTH FROM THERE
INTO THE AFTERNOON. WINDS WILL SPIN ABRUPTLY OUT OF THE NORTH
BEHIND THE COLD FRONT THIS MORNING INTO AFTERNOON. THE
NORTHWESTERN COUNTIES WILL HAVE FROPA BY 12-14Z THIS MORNING. THE
FRONT WILL CONTINUE ACROSS CENTRAL AND SOUTHEASTERN IL THROUGHOUT
THE DAY, EXITING THE SOUTHEAST BY 00Z. WIND GUSTS WILL DECREASE TO
15-20 KNOTS STARTING FROM THE NW AROUND 06Z TONIGHT TO THE SE BY
12Z TOMORROW. THERE IS A 30-50% CHANCE OF GUSTS EXCEEDING 40 MPH
THIS MORNING FROM NOW UNTIL 12Z NORTH OF I-72. THEN THERE IS A
30-60% CHANCE OF EXCEEDING 40 MPH THIS EVENING (23Z-03Z) FOR
EASTERN IL (EAST OF I-55).
TONIGHT INTO MONDAY, THERE IS A 40-70% CHANCE OF SHOWERS AND
THUNDERSTORMS AS A COLD FRONT PASSES THROUGH, FOCUSED ALONG AND EAST
OF I-57. THE GREATEST RISK FOR SEVERE STORMS IS CONCENTRATED NEAR
AND SOUTH OF THE I-70 CORRIDOR. SPC HAS MAINTAINED A MARGINAL RISK
(LEVEL 1 OF 5) FOR AREAS SOUTHEAST OF A PANA TO DANVILLE LINE, AND A
SLIGHT RISK (LEVEL 2 OF 5) THAT EXTENDS EAST OF A OLNEY TO ROBINSON
LINE. THE CAMS GENERALLY DEPICT THE STORMS
DEVELOPING/STRENGTHENING EARLY EVENING AROUND 23-00Z NEAR THE I-70
CORRIDOR, THEN EXITING PRETTY QUICKLY TO THE SOUTH BY 03-04Z. THE
FORECAST SOUNDINGS (GFS, NAMNEST, GDPS, HRRR) FOR SOUTHEASTERN IL
ARE SHOWING AN "INVERTED-V" PROFILE. MOST OF THE MODELS ARE
SHOWING MUCAPE VALUES OF 1500-2000 J/KG, BUT THEN YOU HAVE THE
NAMNEST THAT SHOWS NEARLY 3000 J/KG. DCAPE VALUES ARE GENERALLY
AROUND 900-1000 J/KG. EFFECTIVE WIND SHEAR HAS VALUES OF 30-40
KNOTS. IF WE CAN OVERCOME THE DECENT CAPPING IN PLACE AND IF WE
CAN MOISTEN THE ATMOSPHERE SUFFICIENTLY, THEN WE COULD SEE SEVERAL
SEVERE STORMS. BASED OFF THE FORECAST SOUNDINGS, IT APPEARS THE
PRIMARY RISK WOULD BE FOR DAMAGING WINDS BUT LARGE HAIL COULD ALSO
BE POSSIBLE. DECENT MIDLEVEL LAPSE RATES ARE SEEN IN THE MODELS
WITH 8.0-8.5 C/KM.
BEHIND THE FRONT, THERE IS A NEARLY 30 DEGREE TEMPERATURE CHANGE
STARTING OVERNIGHT TONIGHT. LOWS TONIGHT AND TOMORROW NIGHT WILL DIP
INTO THE LOW TO MID 30S. HIGHS ON MONDAY WILL ONLY TOP OUT IN THE
LOW TO MID 50S. THESE COOLER DAYTIME TEMPERATURES DON'T LAST LONG AS
WE SHOULD BE BACK UP IN THE UPPER 70S TO LOW 80S BY THURSDAY. THEN
ANOTHER COLD FRONT WILL MOVE THROUGH LATE THURSDAY, BRINGING THE
NEXT BEST CHANCE FOR FOR RAIN (30-50%) AND COOLER TEMPERATURES (LOW
TO MID 50S) FOR THE END OF THE WEEK. THOUGH THE NBM THREW IN SOME
LOW CHANCE (10-20%) POPS FROM WEDNESDAY MORNING ONWARD. THIS NEXT
SYSTEM THURSDAY NIGHT MAY HAVE SOME HYDRO CONCERNS BUT FOR NOW WE
WILL CONTINUE TO MONITOR TRENDS AS WE MOVE INTO THE NEW WEEK.
COPPLE
AVIATION
(FOR THE 12Z TAFS THROUGH 12Z MONDAY MORNING)
ISSUED AT 554 AM CDT SUN MAR 22 2026
LLWS WILL END THIS MORNING BY 14Z AS A COLD FRONT STARTS TO SAG
INTO CENTRAL IL, BUT WILL INITIALLY START OUT AT 45 KNOTS AT 1500
FEET. THIS FRONT WILL CAUSE THE SOUTHWEST WINDS TO SHIFT OUT OF
THE NORTH LATER THIS MORNING. WINDS WILL GUST 25-35 KNOTS BEHIND
THE FRONT. THEY WILL LAST INTO THE OVERNIGHT HOURS BUT SHOULD
BEGIN TO LIGHTEN UP TO 6-12 KNOTS BY THE END OF THE 12Z TAF
PERIOD.
VFR CONDITIONS SHOULD LAST THROUGH THE PERIOD, BUT SOME LOWERED
SCATTERED CEILINGS AROUND 3000 FEET MAY OCCUR JUST BEHIND THE
FRONT THIS AFTERNOON. THEN OVERNIGHT, LOWERED MVFR CEILINGS MAY
ADVECT FROM LAKE MICHIGAN, WHICH WAS INCLUDED IN THE CMI TAF TO
SHOW THE TREND. DEC/BMI MAY SEE SOME MVFR CEILINGS BUT CONFIDENCE
IS LOWER FOR THOSE TWO SITES. CMI ALSO HAS VCSH AS THE FRONT
DEVELOPS SHOWERS AND THUNDERSTORMS LATE THIS AFTERNOON.
COPPLE
ILX WATCHES/WARNINGS/ADVISORIES
NONE.
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