927
FXUS63 KILX 180914
AFDILX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE LINCOLN IL
414 AM CDT SUN MAY 18 2025
KEY MESSAGES
- AFTER A NICE LATE SPRING DAY TODAY, UNSETTLED WEATHER RETURNS TO
CENTRAL AND SOUTHEAST IL LATE TONIGHT THROUGH WEDNESDAY, WITH
SEVERAL ROUNDS OF SHOWERS AND THUNDERSTORMS EXPECTED DURING THIS
PERIOD. SOME OF THE THUNDERSTORMS COULD BE SEVERE ON MONDAY
NIGHT AND TUESDAY. LOCALLY HEAVY RAINFALL IN EXCESS OF 2 INCHES
IS ALSO POSSIBLE (40-60% CHANCE).
DISCUSSION
ISSUED AT 345 AM CDT SUN MAY 18 2025
THE 08Z/3 AM SURFACE MAP SHOWS 1024-1027 MB CANADIAN HIGH
PRESSURE OVER MANITOBA AND NOSING DOWN INTO IA AND WEST CENTRAL
IL. A FRONTAL BOUNDARY SOUTH OF IL EXTENDED FROM 999 MB LOW
PRESSURE IN SOUTHEAST COLORADO (SOUTHEAST OF PUEBLO) TO FAR
NORTHERN PARTS OF OK AND AR EASTWARD INTO CENTRAL TN. NORTH OF IL
A COLD FRONT WAS OVER CENTRAL PARTS OF WI AND LOWER MI INTO
SOUTHEAST ONTARIO PROVINCE AND TO 994 MB LOW PRESSURE IN SOUTH
CENTRAL QUEBEC PROVINCE (NW OF QUEBEC CITY). MCS ACTIVITY OVER
NORTHEAST OK AND NORTHERN MS WHILE MORE CONVECTION WAS OVER
CENTRAL AND WEST CENTRAL PARTS OF MO MOVING EAST. MID AND HIGH
CLOUDS (15-25K FT) AHEAD SPREAD INTO CENTRAL IL, WITH THE THICKER
MID LEVEL CLOUDS SE OF I-70 AND IN WEST CENTRAL IL. SEASONABLY
COOL TEMPS WERE IN THE LOW TO MID 50S OVER CWA WITH GALESBURG AT
46F AND MACOMB AND PERU 49F. DEWPOINTS RANGED FROM UPPER 30S AND
LOWER 40S FROM MACOMB TO BLOOMINGTON NORTH TO THE LOWER 50S IN
SOUTHEAST IL FROM EFFINGHAM TO ROBINSON SOUTH. WEST TO NW WINDS
LESS THAN 10 MPH PREVAILED OVER THE AREA EARLY THIS MORNING.
THE CONVECTION IN CENTRAL MO TO MOVE ESE OVER SOUTHERN IL DURING
THIS MORNING AND STAYS ALONG AND SOUTH OF I-64. MID AND HIGH
CLOUDS THAT ARE INCREASING INTO MID MORNING TO THEN DECREASE
LATER THIS MORNING WITH MOSTLY SUNNY SKIES THIS AFTERNOON. A NICE
DAY AHEAD OF CENTRAL AND SOUTHEAST IL WITH LIGHTER WINDS AND
SEASONABLE HIGHS IN THE MID TO UPPER 70S. A BACK DOOR COLD FRONT
COMES SW FROM LAKE MI AND MOVES SW THROUGH CENTRAL IL DURING MID
EVENING INTO EARLY OVERNIGHT (AROUND DUSK REACHING NEAR I-74) WITH
BREEZY EAST TO NE WINDS GUSTING 20-25 MPH MARKING ITS PASSAGE.
THE LATEST SUITE OF FORECAST MODELS DEEPEN LOW PRESSURE AS IT
SLOWLY TRACKS INTO CENTRAL NEBRASKA BY DAWN MONDAY WHILE WARM
FRONT MOVES SLOWLY NE INTO SW MO AND REACHING SOUTHERN/SW TIP OF
IL BY SUNSET MONDAY. MODELS ARE SLOWER WITH BRINGING CONVECTION NE
INTO CENTRAL IL OVERNIGHT AND LOOKS MORE LIKE AFTER 3 OR 4 AM TO
SEE SHOWERS AND ISOLATED THUNDERSTORMS SPREAD INTO AREA AHEAD OF
WARM FROM. SPC DAY1 OUTLOOK KEEPS SLIGHT AND MARGINAL RISK OF
SEVERE STORMS SW OF CWA THROUGH SUNRISE MONDAY, WITH MARGINAL RISK
OVER SW CORNER OF SCOTT COUNTY FOR HAIL THREAT LATE TONIGHT. LOWS
OVERNIGHT AROUND 50F FROM I-74 NE AND MID TO UPPER 50S IN
SOUTHEAST IL AND FROM SPRINGFIELD SW.
SCATTERED SHOWERS AND ISOLATED THUNDERSTORMS OVER CENTRAL IL
DURING EARLY/MID MONDAY MORNING TO BECOME MORE WIDELY SCATTERED
DURING LATE MON MORNING AND MON AFTERNOON AS LOSING INFLUENCE OF
LOW LEVEL JET TO OUR WEST. HIGHS MONDAY MOSTLY IN THE LOWER 70S
WITH MID 70S FROM HIGHWAY 50 SOUTH. MORE WIDESPREAD CONVECTION TO
DEVELOP DURING MONDAY EVENING AND INTO OVERNIGHT HOURS WITH WARM
FRONT LIFTING NE INTO CENTRAL IL LATE MON NIGHT AND INCREASE LOW
LEVEL JET. SPC DAY2 OUTLOOK CONTINUES MARGINAL TO SLIGHT RISK OF
SEVERE STORMS MONDAY NIGHT OVER CWA, WITH THE SLIGHT RISK FROM
CANTON TO SPRINGFIELD WEST WHERE TORNADO THREAT WILL BE ALONG WITH
HATCHED AREA OF LARGE HAIL STONES LARGER THAN 2 INCHES POSSIBLE
(10% CHANCE WITHIN 25 MILES OF A POINT). LOW PRESSURE MOVES INTO
IOWA DURING TUE WITH ANOTHER LOW PRESSURE INTO CENTRAL IL AND
LIFTING WARM FRONT NORTHWARD THROUGH HEART OF CENTRAL IL. SPC DAY
3 OUTLOOK HAS MARGINAL TO SLIGHT RISK OF SEVERE STORMS FROM IL
RIVER SE WITH THE SLIGHT RISK FROM JACKSONVILLE TO LINCOLN TO
DANVILLE SOUTH. ALL SEVERE WX ELEMENTS AT PLAY HERE ON TUE INTO
EARLY TUE EVENING. GREATEST THREAT OF STRONGER SEVERE STORMS IS
OVER FAR SOUTHERN IL INTO WESTERN KY, AND MID/WEST TN. WPC ERO HAS
SLIGHT RISK OF EXCESSIVE RAINFALL MON NIGHT INTO TUE OVER MUCH OF
AREA WITH 40-60% CHANCE OF SEEING GREATER THAN 2 INCHES OF
RAINFALL. WE WILL HAVE MORE OF A TEMPERATURE GRADIENT ON TUE
DEPENDING ON HOW FAR WARM FRONT GETS. HIGHS IN THE MID TO UPPER
60S FROM I-74 NORTH AND MID TO UPPER 70S FROM SPRINGFIELD TO
TERRE HAUTE SOUTH.
A LARGE MID/UPPER LEVEL TROF OVER THE MIDWEST WED WITH A SURFACE
TROF HANGING BACK OVER NORTHERN/NE IL TO KEEP CHANCES OF SHOWERS
AND MORE CLOUDS AROUND ON WED AND INTO WED NIGHT ESPECIALLY DURING
THE EVENING HOURS. COOL HIGHS WED AROUND 60F TO LOWER 60S WITH
MID 60S FAR SE CWA BY THE WABASH RIVER VALLEY. BREEZY NW WINDS WED
TO MAKE IT FEEL COOLER. COOL LOWS WED NIGHT IN THE MID TO UPPER
40S AND LOW TO MID 40S FOR LOWS THU NIGHT. HIGHS THU STILL COOL IN
THE LOW TO MID 60S AND STILL COULD BE ISOLATED LIGHT SHOWERS
AROUND ON THU WITH DEEP MID/UPPER LEVEL TROF NEARBY IN THE CENTRAL
GREAT LAKES AND DOWN INTO THE APPALACHIANS. IL ESTABLISHED IN A NW
UPPER LEVEL FLOW LATE THIS WEEK AND TEMPS TO SLOWLY MODIFY FRI AND
SAT BUT STILL BE BELOW NORMAL BY 5-10 DEGREES. BLENDED FORECAST
BRINGS 20% CHANCE OF SHOWERS SATURDAY AND 30-40% CHANCE OF
SHOWERS AND ISOLATED THUNDERSTORMS SUNDAY THOUGH LARGE MODEL
DIFFERENCES WITH WX SYSTEMS MOVING THROUGH THE MIDWEST AND HOW
QUICKLY UPPER LEVEL TROF EXITS TO OUR NORTHEAST.
07
AVIATION
(FOR THE 06Z TAFS THROUGH 06Z SUNDAY NIGHT)
ISSUED AT 1222 AM CDT SUN MAY 18 2025
HIGH PRESSURE WILL MOVE ACROSS THE REGION SUNDAY. EXPECT
DIMINISHING NORTHWEST WINDS AHEAD OF THE RIDGE AXIS BECOMING
LIGHT AND VARIABLE. AN ENHANCED LAKE BREEZE OFF OF LAKE MICHIGAN
WILL PUSH ACROSS CENTRAL ILLINOIS LATE IN THE EVENING TURNING
WINDS NE/E 10-14 KTS. VFR CONDITIONS ARE EXPECTED THROUGH THE
PERIOD.
DEUBELBEISS
ILX WATCHES/WARNINGS/ADVISORIES
NONE.
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