355
FXUS63 KILX 290509
AFDILX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE LINCOLN IL
1209 AM CDT WED APR 29 2026
KEY MESSAGES
- SHOWERS AND STORMS ARE LIKELY THIS EVENING INTO TONIGHT,
PRIMARILY EAST OF THE IL RIVER. THE BEST CHANCE FOR RAINFALL
TOTALS OVER A HALF INCH IS NEAR AND SOUTH OF I-70 (60-80%
CHANCE). SEVERE STORMS ARE NOT EXPECTED.
- BELOW NORMAL TEMPERATURES PERSIST THROUGH SATURDAY. FROST IS
POSSIBLE FRIDAY NIGHT INTO EARLY SATURDAY MORNING AS LOWS
FALL INTO THE MID 30S.
UPDATE
ISSUED AT 914 PM CDT TUE APR 28 2026
SOME OF THE RETURNS ON RADAR ACROSS THE NORTHERN PART OF THE CWA
IS FINALLY REACHING THE GROUND, BUT GUESSING MOST OF IT IS NOT
REACHING THE GROUND AND IS JUST VIRGA. HOWEVER, ADDITIONAL
PRECIP IS STILL EXPECTED TO DEVELOP AND MOVE ACROSS THE AREA THE
REMAINDER OF THE NIGHT, ENDING AROUND MORNING. ANY THUNDERSTORMS
SHOULD REMAIN TO THE SOUTHEAST OF I-72/DANVILLE. UPDATE SHOULD
BE COMING SHORTLY.
DISCUSSION
ISSUED AT 125 PM CDT TUE APR 28 2026
CURRENT ANALYSIS SHOWS A SHORTWAVE CURRENTLY OVER THE MID-
MISSOURI VALLEY, PROGGED TO TRACK INTO CENTRAL ILLINOIS TONIGHT.
HIGH- RESOLUTION GUIDANCE (HRRR/RAP) INDICATES RAIN SHOWERS
WILL OVERSPREAD THE AREA FROM WEST TO EAST AFTER 00Z. THE HREF
DENOTES A HIGH PROBABILITY (90%+) OF RAINFALL TOTALS EXCEEDING
0.10 INCHES SOUTH OF I-72, WITH LOCALIZED AMOUNTS OF 0.50-1.00
INCHES IN SOUTHEAST ILLINOIS WHERE BETTER MOISTURE CONVERGENCE
RESIDES. HIGHER PROBABILITIES OF THUNDER ALSO EXIST SOUTH OF
I-70 WHERE SOME ELEVATED INSTABILITY WILL BE PRESENT. WHILE WE
DO NOT EXPECT SEVERE STORMS IN THE LOCAL AREA, SPC'S MARGINAL
AND SLIGHT RISK AREAS ARE JUST TO THE SOUTH IN SOUTHERN IL.
WINDS WILL SHIFT TO NORTHERLY BEHIND THE WAVE BY WEDNESDAY
MORNING, WITH GUSTS REACHING 20-25 MPH. THE COLD ADVECTION WILL
RESULT IN ANOTHER COOL DAY WITH HIGHS IN THE LOW TO MID 60S.
A DEEP UPPER- LEVEL TROUGH REMAINS ANCHORED OVER THE EASTERN
HALF OF THE CONUS INTO THIS WEEKEND. STRONG COLD AIR ADVECTION
WILL SUPPRESS HIGH TEMPERATURES INTO THE 50S TO LOW 60S, WHICH
IS ROUGHLY 10-15 DEGREES BELOW CLIMATOLOGICAL NORMS. DRY
CONDITIONS WILL DOMINATE, WITH THE EXCEPTION OF A FAST- MOVING
BUT MOISTURE- STARVED SHORTWAVE CROSSING THE REGION THURSDAY
NIGHT. WILL STICK WITH NBM'S 10-20% CHANCE OF SHOWERS FOR THIS
PERIOD.
THE PRIMARY CONCERN LATE THIS WEEK IS THE POTENTIAL FOR FROST
LATE FRIDAY NIGHT INTO SATURDAY MORNING. HIGH PRESSURE IS
FORECAST TO SETTLE OVER THE MID- MISSISSIPPI VALLEY, LEADING TO
CLEARING SKIES AND DIMINISHING WINDS. THE ECMWF EFI SHOWS A
SIGNIFICANT SIGNAL FOR ANOMALOUS COLD, AND NBM 10TH PERCENTILE
TEMPERATURES SUGGEST LOWS IN THE LOWER 30S ARE FEASIBLE IN RURAL
AND LOW- LYING AREAS. HIGH CONFIDENCE (70-80%) EXISTS IN SEEING
FROST ACROSS MUCH OF CENTRAL ILLINOIS DURING THIS TIME. THOSE
WITH SENSITIVE VEGETATION MAY NEED TO TAKE PROTECTIVE ACTION.
SUNDAY THROUGH TUESDAY... RAIN CHANCES RETURN FOR MONDAY AND
TUESDAY, THOUGH SPECIFIC TIMING REMAINS LOW CONFIDENCE DUE TO
THE VARIANCE IN ENSEMBLE CLUSTERS. THERE IS A BETTER SIGNAL FOR
TEMPERATURES REBOUNDING TO SEASONABLE LEVELS EARLY NEXT WEEK
ACROSS A RANGE OF GUIDANCE, SUPPORTED BY RISING MID LEVEL
HEIGHTS.
AVIATION /06Z TAFS THROUGH 06Z THURSDAY/
ISSUED AT 1208 AM CDT WED APR 29 2026
SCATTERED LIGHT SHOWERS ARE ONGOING AT THE START OF THE PERIOD.
THESE WILL END FROM WEST TO EAST BETWEEN 08-10Z, AND THE REST OF
THE PERIOD SHOULD BE DRY. WHILE THERE IS A LOW CHANCE OF MVFR
CEILINGS WITH THE SHOWERS, HAVE NOT SEEN ENOUGH SFC OBS OF MVFR
ALONG AND NORTH OF I-72 TO SUPPORT KEEPING IT IN THE TEMPO
GROUPS. THUS, VFR IS FORECAST TO PREVAIL THROUGH THE PERIOD,
ALONG WITH NORTHWEST WINDS WHICH COULD GUST 20-25 KTS DURING THE
AFTERNOON.
ILX WATCHES/WARNINGS/ADVISORIES
NONE.
KEY MESSAGES...25
UPDATE...AUTEN
DISCUSSION...25
AVIATION...ERWIN
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