933
FXUS63 KILX 301748
AFDILX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE LINCOLN IL
1248 PM CDT MON MAR 30 2026
KEY MESSAGES
- PERIODS OF SHOWERS AND STORMS ARE FORECAST FROM TUESDAY
THROUGH SATURDAY. THERE IS A 50-80% CHANCE RAIN TOTALS EXCEED
2 INCHES, WITH THE HIGHEST CHANCES NORTH OF I-72/DANVILLE;
THIS WOULD FURTHER ALLEVIATE ONGOING DROUGHT CONDITIONS.
- THERE IS A LEVEL 1 OF 5 (MARGINAL) RISK FOR SEVERE WEATHER
TUESDAY AFTERNOON AND EVENING. CONFIDENCE IS LOW IN WHETHER A
SEVERE WEATHER RISK CAN MATERIALIZE WEDNESDAY THROUGH
SATURDAY.
- WINDY CONDITIONS ARE FORECAST BOTH TUESDAY AND THURSDAY, WITH
AROUND A 50-60% CHANCE GUSTS OUT OF THE SOUTHWEST SURPASS 40
MPH BOTH DAYS. THIS COULD CAUSE DIFFICULT DRIVING CONDITIONS
FOR HIGH PROFILE VEHICLES, AND BLOW AROUND LIGHTWEIGHT OBJECTS
SUCH AS UNANCHORED HOLIDAY DECORATIONS.
DISCUSSION
ISSUED AT 239 AM CDT MON MAR 30 2026
***** WARM AND DRY TODAY, SCATTERED STORMS TUESDAY *****
EARLY MONDAY MORNING, SOUTH-SOUTHWESTERLY WINDS WERE HOLDING
TEMPERATURES IN THE MID-UPPER 50S ACROSS CENTRAL AND SOUTHEAST IL.
WITH THIS MILD START TO THE DAY, WE SHOULD HAVE NO TROUBLE WARMING
INTO THE MID 70S TO LOW 80S THIS AFTERNOON - WARMEST IN WEST-CENTRAL
IL WHERE THE LOW LEVEL AIRMASS WILL BE DRIER AND HENCE LOW LEVEL
CLOUDS WILL BE FEWER. LOW LEVEL MOISTURE WILL NONETHELESS CLIMB
DURING THE DAY ON SOUTH-SOUTHWEST WINDS GUSTING 20-30 MPH, WITH
DEWPOINTS SOLIDLY IN THE 50S BY EVENING WHEN AN EML ADVECTED
INTO NORTHWEST IL WILL FOSTER STEEP (~9 DEGC/KM) 700-500MB LAPSE
RATES AND HENCE 1500-3000 J/KG ELEVATED CAPE. WEAK FORCING
SHOULD KEEP CONVECTION FROM FIRING IN OUR CWA, THOUGH ONE CAN'T
GUARANTEE WE WON'T BE CLIPPED BY SOMETHING THAT DEVELOPS
UPSTREAM ACROSS NORTHERN MO/SOUTHEAST IA WHERE CAPPING IS
WEAKER. THE HRRR AND RRFS ARE AGGRESSIVE WITH WINDS ASSOCIATED
WITH THIS ACTIVITY, AS EVAPORATIONAL COOLING (SOUNDINGS REVEAL
PROLIFIC DRY AIR IN THE MID LEVELS) MIXES DOWN THE LLJ FOR 50-70
MPH SFC GUSTS, BUT SO FAR THEY EACH KEEP THIS FOCUSED NEAR I-80
(NORTH OF OUR CWA) TOMORROW NIGHT.
A MORE FAVORABLE DYNAMIC ENVIRONMENT FOR CONVECTION WILL SET UP OVER
OUR NECK OF THE WOODS TOMORROW, THOUGH WE'LL HAVE QUITE THE CAPPING
INVERSION TO OVERCOME WITH RELATIVELY WEAK UPPER LEVEL FORCING. CAM
OUTCOMES DIFFER FROM ONE ANOTHER (AND RUN TO RUN), SO IT'S DIFFICULT
TO DISCERN WHETHER ANYTHING AHEAD OF THE COLD FRONT CAN LIFT PARCELS
TO THE LFC OR NOT. HREF MEAN SUGGESTS 500-1500 J/KG MUCAPE, ROOTED
AROUND 750MB PER FORECAST SOUNDINGS, WHICH WOULD BE SUFFICIENT TO
SUSTAIN A FEW SEVERE STORMS GIVEN 35-45KT 0-6KM SHEAR, SO SPC'S
LEVEL 1 OF 5 (MARGINAL) RISK SEEMS WARRANTED. OUTSIDE OF STORMS,
TOMORROW WILL BE WARM AND WINDY, WITH THE REFS AND HREF ENSEMBLES
ADVERTISING A 40-60% CHANCE SOUTHWESTERLY WINDS GUST OVER 40 MPH.
***** COOLER AND RAINY WEDNESDAY *****
WITH UPPER LEVEL FORCING DISPLACED WELL TO THE NORTH, THE FRONT WILL
GET HUNG UP SOMEWHERE NEAR OR OVER OUR AREA TUESDAY NIGHT INTO
WEDNESDAY, EVENTUALLY LIFTING BACK NORTHWARD AS ANOTHER SFC LOW
APPROACHES ALONG IT WEDNESDAY NIGHT INTO THURSDAY. CONSEQUENTLY, THE
SERIES OF WEAK DISTURBANCES RIPPLING THROUGH THE AREA WILL INTERACT
WITH THE FRONT TO TRIGGER CONTINUED SHOWERS AND PERHAPS A FEW
RUMBLES OF THUNDER OVERNIGHT TUESDAY NIGHT RIGHT ON THROUGH
WEDNESDAY NIGHT, WITH NBM GIVING A 50-75% CHANCE FOR MORE THAN AN
INCH OF RAINFALL NORTH OF I-70 BY DAWN THURSDAY MORNING. WEDNESDAY
WILL BE CHILLY NORTH OF THE FRONT, WITH TEMPERATURES IN THE MID 40S
TO LOW 50S AND SUSTAINED 15-20 MPH EASTERLY WINDS KEEPING FEELS LIKE
TEMPS ABOUT 10 DEGREES COOLER. MEANWHILE, THE NBM GIVES AREAS ALONG
HWY 50 A 20-30% CHANCE OF REACHING 80 DEGREES. THESE AREAS (AND
FURTHER NORTH TO ROUGHLY I-70) WILL BEAR WATCHING FOR SEVERE
CONVECTION WEDNESDAY AFTERNOON AND EVENING, AS THE RRFS DEVELOPS A
FEW CELLS ALONG A NARROW RIBBON OF SFC BASED INSTABILITY ALONG A
BOUNDARY THERE FROM 3-7PM.
***** MILDER WITH SCATTERED STORMS THURSDAY INTO FRIDAY *****
THE DETERMINISTIC MODELS GENERALLY AGREE THAT A SFC LOW WILL DEVELOP
BENEATH AN INCREASINGLY NEGATIVELY TILTED SHORTWAVE TROUGH LIFTING
FROM THE SOUTHERN PLAINS INTO THE UPPER MIDWEST WEDNESDAY NIGHT INTO
THURSDAY NIGHT. THE GEFS AND EPS GENERALLY AGREE THE SFC LOW WILL
TRACK THROUGH EITHER FAR WESTERN ILLINOIS OR, MORE LIKELY, EASTERN
IOWA, PLACING OUR AREA IN THE WARM SECTOR ON THURSDAY. WHILE
DEWPOINTS WILL CLIMB SOLIDLY INTO THE 60S, SFC HEATING WILL BE
LIMITED BY CLOUD COVER AND ANY ONGOING EARLY-DAY CONVECTION, AND MID
LEVEL LAPSE RATES APPEAR POOR AT ONLY 6.5-7 DEGC/KM - CONFINING
MUCAPES TO AROUND 500-1500 J/KG. NONETHELESS, THE 30-45 KT OF DEEP
LAYER SHEAR THE GFS IS ADVERTISING SUGGESTS THIS SET-UP WILL BEAR
WATCHING FOR SEVERE STORMS, PARTICULARLY IF THE LOW LIFTS THROUGH
THE AREA DURING THE EVENING WHEN LOW LEVEL SHEAR IS INCREASED BY THE
LLJ. A TIGHT PRESSURE GRADIENT ASSOCIATED WITH THAT LOW MAY ALSO
PROMOTE ANOTHER DAY OF STRONG SOUTHWEST WINDS, WITH THE EPS MEAN
NORTH OF 40 MPH.
***** STRONGER SYSTEM ARRIVING THIS WEEKEND *****
THE AIRMASS WILL REMAIN MILD IN THE WAKE OF THAT LOW WITH YET
ANOTHER ONE DEVELOPING UPSTREAM LATE FRIDAY INTO SATURDAY. THE GFS
AND PARTICULARLY THE ECMWF SUGGEST THE UPPER LEVEL FORCING WITH THIS
SYSTEM WILL BE STRONGER WITH A DEEP 500MB LOW LIFTING THROUGH THE
MIDWEST. EPS MEAN BRINGS MUCAPES TO 300-600 J/KG FRIDAY NIGHT INTO
SATURDAY, WITH LESS THAN A 15% CHANCE VALUES EXCEED 1000 J/KG AHEAD
OF THE COLD FRONT ON SATURDAY - SUGGESTING INSTABILITY WILL ONCE
AGAIN BE THE LIMITING FACTOR. NONETHELESS, WE'RE CONCERNED STORMS
FRIDAY NIGHT INTO SATURDAY MORNING COULD PRODUCE LARGE HAIL GIVEN
THE STRONG WIND SHEAR AND MODEST MID-LEVEL LAPSE RATES (7-8
DEGC/KM). IN ADDITION, A STRONGLY FORCED LINE ALONG THE COLD FRONT
MID MORNING INTO EARLY/MID SATURDAY AFTERNOON COULD GENERATE
DAMAGING WINDS WITH LITTLE INSTABILITY GIVEN THE KINEMATIC FIELDS
(50KT WINDS AT 900MB).
BETWEEN ALL OF THESE WAVES OF PRECIPITATION, NBM GIVES THE AREA A 50-
75% CHANCE RAIN TOTALS EXCEED 2 INCHES, WITH LREF PROBABILITIES EVEN
HIGHER - AROUND 65-80%; THIS SHOULD FURTHER RELIEVE THE ONGOING
DROUGHT CONDITIONS ACROSS THE STATE. ONCE THE FRONT CROSSES THE AREA
SATURDAY OR SATURDAY NIGHT, MUCH COOLER CONDITIONS WILL OVERSPREAD
THE REGION WITH NBM GIVING A 20-50% CHANCE FOR LOW TEMPERATURES
BELOW FREEZING SUNDAY NIGHT.
AVIATION /18Z TAFS THROUGH 18Z TUESDAY/
ISSUED AT 1248 PM CDT MON MAR 30 2026
VFR CONDITIONS WILL PREVAIL THROUGH THE ENTIRE 18Z TAF PERIOD.
ASIDE FROM FEW-SCT MID CLOUDS ALONG/EAST OF I-57, SKIES WILL
REMAIN CLEAR THROUGH THE REMAINDER OF THE AFTERNOON BEFORE HIGH
CLOUDS SPREAD ACROSS THE REGION FROM WEST TO EAST THIS EVENING.
SCATTERED CONVECTION WILL DEVELOP NEAR A NEARLY STATIONARY
FRONTAL BOUNDARY FROM CENTRAL IOWA NORTHEASTWARD TO THE CHICAGO
AREA TONIGHT, BUT THE MAJORITY OF THIS ACTIVITY WILL REMAIN
WELL NORTH OF THE TERMINALS. THE POTENTIAL EXCEPTION WILL BE
KPIA WHERE VCSH HAS BEEN ADDED BETWEEN 07Z AND 14Z. FURTHER
SOUTH, NAM FORECAST SOUNDINGS SUGGEST BKN CLOUDS AT 4000-5000FT
DEVELOPING WELL AFTER DARK, THEN PERSISTING THROUGH MIDDAY
TUESDAY. WINDS WILL INITIALLY BE SW WITH GUSTS OF 25-30KT
ALONG/WEST OF I-55...AND 30-35KT FURTHER EAST TODAY. THE GUSTS
WILL TEMPORARILY SUBSIDE BY SUNSET, WITH SUSTAINED WINDS OF
10-15KT CONTINUING THROUGH THE NIGHT. AS WAS THE CASE LAST
NIGHT, A STRONG LOW-LEVEL JET WILL DEVELOP OVERHEARD...LEADING
TO 40-50KT OF LOW-LEVEL WIND SHEAR. ONCE DAYBREAK ARRIVES, SOME
OF THIS MOMENTUM WILL GET MIXED TO THE SURFACE AFTER 14Z WITH
WINDS ONCE AGAIN GUSTING 25-30KT ALONG/WEST OF I-55 AND 30-35KT
TO THE EAST.
ILX WATCHES/WARNINGS/ADVISORIES
NONE.
KEY MESSAGES...BUMGARDNER
DISCUSSION...BUMGARDNER
AVIATION...BARNES
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