496
FXUS63 KILX 301720
AFDILX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE LINCOLN IL
1220 PM CDT THU APR 30 2026
KEY MESSAGES
- CHANCES OF RAIN SHOWERS HAVE INCREASED FOR THIS AFTERNOON AND
EVENING (40-60%). WHILE AMOUNTS SHOULD BE RELATIVELY LIGHT,
SOME GUSTY WINDS WILL ACCOMPANY THE HEAVIER SHOWERS.
ADDITIONAL SHOWERS ARE EXPECTED FRIDAY AFTERNOON, THOUGH
CONFIDENCE IS LOWER (20% CHANCE).
- WHILE FROST REMAINS A CONCERN FOR FRIDAY NIGHT, ADDITIONAL
CLOUD COVER INTRODUCES SOME UNCERTAINTY.
- THE OVERALL WEATHER PATTERN THE NEXT WEEK WILL FAVOR
TEMPERATURES BELOW NORMAL, WITH ONLY SUNDAY AND MONDAY
REACHING NEAR CLIMATOLOGICAL NORMALS (LOW 70S FOR EARLY MAY).
DISCUSSION
ISSUED AT 215 AM CDT THU APR 30 2026
THE BIG PICTURE:
EARLY MORNING WATER VAPOR IMAGERY CONTINUES TO SHOW AN UPPER LOW
OVER LAKE SUPERIOR, WITH THE NEXT IN A SERIES OF SHORTWAVES
DROPPING SOUTHEAST ACROSS THE DAKOTAS AND MINNESOTA. THE
PROJECTED UPPER PATTERN TO START MAY HAS NOT SIGNIFICANTLY
CHANGED, WITH THE UPPER LOW DOMINATING THE GREAT LAKES REGION
BEFORE LIFTING NORTHEAST THIS WEEKEND, ONLY TO BE FOLLOWED BY
ADDITIONAL LOBES OF LOW PRESSURE EXPANDING OVER SOUTH CENTRAL
CANADA NEXT WEEK. AS A RESULT, TEMPERATURES GENERALLY WILL
REMAIN ON THE COOLER SIDE FOR THIS TIME OF YEAR, WITH A BRIEF
WARMUP FOR SUNDAY AND MONDAY.
SHORT TERM (THROUGH SATURDAY):
WITH THE SERIES OF UPPER WAVES DROPPING SOUTHEAST, RAIN CHANCES
ARE A CONCERN FOR TODAY, AND FRIDAY TO A LESSER EXTENT. HAVE
BOOSTED POP'S FOR THIS AFTERNOON AND EVENING WITH THE WAVE
MOVING THROUGH, AND THEY ARE NOW IN THE 50-60% RANGE WEST OF
I-55 THIS AFTERNOON AND EAST OF THERE IN THE EVENING. HOWEVER,
FORECAST SOUNDINGS SHOW THE CLOUD BASES BEING RELATIVELY HIGH
(5000-7000 FEET) WITH CONSIDERABLE DRY AIR BELOW THAT, SO
ACCUMULATIONS SHOULD BE RELATIVELY MODEST. THE LARGE INVERTED-V
SIGNATURE WOULD SUGGEST SOME GUSTY WINDS WITH THE HEAVIER
SHOWERS, AND A FEW RUMBLES OF THUNDER ARE POSSIBLE GIVEN THE
STEEP LOW LEVEL LAPSE RATES. A SIMILAR SCENARIO MAY UNFOLD ON
FRIDAY, THOUGH WITH THE UPPER WAVE LAGGING BEHIND A BIT, WILL
ONLY GO WITH 20% CHANCES FOR NOW NEAR/WEST OF I-55.
FROST POTENTIAL REMAINS A CONCERN, MAINLY ON FRIDAY NIGHT. WILL
KEEP A MENTION OF AREAS OF FROST FROM ABOUT GALESBURG-PARIS
NORTHEAST. HOWEVER, CLOUD COVER MAY BE MORE OF AN ISSUE, AS THE
BROADER UPPER TROUGH WILL BE SWINGING ACROSS THE STATE. THE
COOLEST WEATHER WILL BE ASSOCIATED WITH THIS TROUGH, WITH HIGHS
FRIDAY AND SATURDAY MAINLY IN THE MID TO UPPER 50S OVER A GOOD
CHUNK OF THE FORECAST AREA.
LONG TERM (SUNDAY THROUGH WEDNESDAY):
ONCE THE UPPER TROUGH SHIFTS EASTWARD, WE'LL GET A SOUTHERLY
FLOW SETTING UP TO START THE NEW WEEK. HIGH TEMPERATURES RETURN
TO THE LOWER 70S WEST OF I-55 SUNDAY, AND 70S WILL BE COMMON
MONDAY OVER THE REGION. THE UPPER PATTERN SHIFTS MORE INTO A
SPLIT FLOW, AS AN UPPER LOW DROPS INTO CALIFORNIA AS THE
CANADIAN TROUGHING DIGS SOUTH. SYNOPTIC MODELS SHOW OUR AREA
CAUGHT IN THE MIDDLE, WITH EXTENDED RAIN CHANCES FROM MONDAY
INTO MIDWEEK. LREF GRAND ENSEMBLE SHOWS PROBABILITIES OF MORE
THAN A HALF INCH OF RAIN PEAKING AROUND TUESDAY NIGHT AND
WEDNESDAY, IN THE 40-50% RANGE. TEMPERATURES EASE BACK AGAIN AS
THE CANADIAN TROUGH DEEPENS AND DIGS INTO THE MID AND UPPER
MISSISSIPPI VALLEY.
AVIATION /18Z TAFS THROUGH 18Z FRIDAY/
ISSUED AT 1220 PM CDT THU APR 30 2026
AN UPPER LEVEL DISTURBANCE IS DIGGING ACROSS THE MID/UPPER
MISSISSIPPI VALLEY EARLY THIS AFTERNOON WITH SCATTERED LIGHT AND
HIGH-BASED SHOWERS SPREADING SE FROM IA INTO IL. THERE COULD BE
SOME GUSTY WINDS AND BRIEF MVFR VISIBILITY IN AND NEAR THE
SHOWERS AS THEY MOVE ACROSS CENTRAL IL THIS AFTERNOON AND
EVENING, OTHERWISE VFR CONDITIONS ARE EXPECTED THROUGH THE
PERIOD. A MODEST SW BREEZE IN PLACE THIS AFTERNOON WILL SET UP
OUT OF THE NW TONIGHT THEN VEER TO NORTHERLY DURING THE DAY
FRIDAY.
ILX WATCHES/WARNINGS/ADVISORIES
NONE.
KEY MESSAGES...GEELHART
DISCUSSION...GEELHART
AVIATION...DEUBELBEISS
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