467
FXUS63 KLOT 251708
AFDLOT
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE CHICAGO/ROMEOVILLE, IL
1208 PM CDT SAT OCT 25 2025
KEY MESSAGES
- SEASONABLE TEMPERATURES THROUGH THE END OF THE MONTH.
- A FEW SPRINKLES ACROSS NORTHERN ILLINOIS TODAY, THEN
INCREASING RAIN CHANCES FOR PORTIONS OF THE AREA TUESDAY INTO
WEDNESDAY.
UPDATE
ISSUED AT 927 AM CDT SAT OCT 25 2025
RECENT KLOT RADAR IMAGERY SHOWS TWO AREAS OF ECHOS: ONE ALONG
THE SOUTHERN BOUNDARY OF THE FORECAST AREA AND ANOTHER IN
SOUTHERN WISCONSIN. WHILE THERE IS HIGHER MID LEVEL MOISTURE
CONTENT IN CENTRAL ILLINOIS, 12Z KILX SOUNDING SHOWS ROBUST LOW
LEVEL DRY AIR LEADING THAT THE RADAR RETURNS ARE MOST LIKELY
VIRGA. A FEW SPRINKLES CANNOT BE COMPLETELY RULED OUT, BUT WITH
WEAK FORCING AND THE AFOREMENTIONED DRY AIR, NOT MUCH IS
EXPECTED SOUTH OF I-80. MEANWHILE, THERE IS SLIGHTLY BETTER
FORCING WITH THE SHORTWAVE MOVING OVER SOUTH CENTRAL WISCONSIN,
AS SEEN ON GOES-19 VAPOR IMAGERY. MOST OF THE SHOWERS WILL
LIKELY REMAIN IN NORTH OF STATELINE, BUT THE MORNING FORECAST
UPDATE MAINTAINS THE MENTION OF SHOWERS/SPRINKLES FOR THE FAR
NORTHEASTERN PORTION OF ILLINOIS. LATEST HIGH-RES GUIDANCE IS
SUGGESTING THAT THERE COULD BE A LOCALIZED AXIS OF CONVERGENCE
ALONG A ROCKFORD TO VALPARAISO LINE THAT COULD BE A FOCAL AREA
FOR SHOWER DEVELOPMENT THIS AFTERNOON, BUT RAIN AMOUNTS SHOULD
BE FAIRLY LIMITED. MOST AREAS WILL REMAIN MOSTLY DRY WITH LIGHT
EAST- SOUTHEAST WINDS AND HIGH TEMPERATURES IN THE LOW TO MID
50S.
DK
DISCUSSION
ISSUED AT 319 AM CDT SAT OCT 25 2025
BLOCKING FROM A PROMINENT RIDGE OVER CENTRAL CANADA AND UPPER-
LEVEL LOW CENTERED OVER OKLAHOMA TODAY WILL PERSIST INTO EARLY
NEXT WEEK, RESULTING IN A SLOW EVOLUTION OF THE BROADER FLOW
ACROSS CENTRAL NORTH AMERICA. PRECIP CHANCES DURING THIS PERIOD
LOOK TO BE QUITE LOW AMID GENERALLY SEASONABLE TEMPERATURES FOR
LATE OCTOBER.
MOSTLY CLEAR SKIES EARLY THIS MORNING WILL GRADUALLY FILL IN
WITH MID AND UPPER-LEVEL CLOUDS FROM BOTH THE NORTHWEST AND
SOUTH THROUGH THE REMAINDER OF THE MORNING. AN AREA OF MODEST
MID-LEVEL MOISTURE EVIDENT IN SATELLITE AND OBS OVER IOWA EARLY
THIS MORNING WILL GRADUALLY ADVECT EASTWARD TODAY AS A COMPACT
WAVE JUST EAST OF THE TWIN CITIES TRACKS SOUTHEASTWARD.
SCATTERED MID-LEVEL SHOWERS HAVE BEEN COMMON ACROSS SOUTHEAST
MINNESOTA AND NORTHERN IOWA THIS MORNING. WITH THE ADDED MID-
LEVEL MOISTURE INTERACTING WITH THE APPROACHING WAVE,
EXPECTATIONS ARE FOR AT LEAST ISOLATED LIGHT SHOWERS OR
SPRINKLES OVER NORTHERN ILLINOIS LATER THIS MORNING INTO THE
AFTERNOON HOURS. FARTHER SOUTH, THE NORTHERN PERIPHERY OF THE
UPPER-LEVEL LOW MAY BRING A FEW SPRINKLES ACROSS CENTRAL
ILLINOIS LATER THIS AFTERNOON AND THIS EVENING, BUT EXPECTATIONS
ARE FOR PRECIP TO REMAIN SOUTH OF THE FORECAST AREA.
MOSTLY CLEAR SKIES ARE THEN IN STORE SUNDAY THROUGH MONDAY AS
SOME ADDITIONAL CIRRUS FROM THE LOW TO THE SOUTH FILTERS
NORTHWARD ACROSS THE AREA.
AS THE UPPER LOW (RIDGE) DRIFTS EASTWARD TO THE SOUTHEASTERN
STATES (WESTERN QUEBEC) BY TUESDAY, A MID-LEVEL LOW DISLODGING
FROM A BROADER TROUGH OVER THE NORTHWEST U.S. WILL UNRAVEL WHILE
ATTEMPTING TO PHASE WITH THE EASTERN LOW. CONSENSUS GUIDANCE
CONTINUES TO COME INTO BETTER AGREEMENT THAT THE LOW WILL PASS
SOUTHWEST OF THE FORECAST AREA TUESDAY AFTERNOON THROUGH
WEDNESDAY. HOWEVER, A RESIDUAL RESERVOIR OF MID-LEVEL MOISTURE
FROM THE EASTERN LOW WILL BE DRAWN INTO THE APPROACHING WAVE AS
THE ENTRANCE REGION OF A NORTHWESTWARD DIRECTED UPPER-LEVEL JET
STREAK SETTLES JUST WEST OF THE FORECAST AREA. THIS SHOULD
SUPPORT A NW TO SE ORIENTED BAND OF RAIN OVER AT LEAST SOME OF
THE FORECAST AREA (ESPECIALLY THE SOUTHWEST HALF) DURING THIS
TIME.
INTERACTIONS WITH THE TWO LOWS LATER IN THE WEEK, AS WELL THE
ANY POTENTIAL INTERACTIONS FROM (CURRENTLY) TROPICAL STORM
MELISSA, SEEM TO POINT TOWARD AN OVERALL TRANSITION TO A
LONGWAVE TROUGH DEVELOPING ACROSS THE EASTERN GREAT LAKES,
NORTHEAST, AND EASTERN CANADA BY EARLY NEXT WEEKEND. ANY WEAK
WAVE ROTATING ON THE WESTERN FLANK OF THE LOW WILL LIKELY YIELD
ISOLATED TO SCATTERED SHOWERS AND PERHAPS SOME A FEW LAKE EFFECT
RAIN SHOWERS DURING THIS TIME. WITH NO ARCTIC AIR MASSES BEHIND
THE BROAD TROUGH, TEMPS SHOULD REMAIN SEASONABLE AS WE CLOSE
OUT OCTOBER.
KLUBER
AVIATION /18Z TAFS THROUGH 00Z MONDAY/
ISSUED AT 1208 PM CDT SAT OCT 25 2025
THERE ARE NO AVIATION WEATHER CONCERNS FOR THE 18Z TAF PERIOD.
EXPECT ESE WINDS LARGELY BELOW 10 KT THROUGH THE REMAINDER OF
TODAY AND TONIGHT. E WINDS 10 TO 15 KT MAY OCCASIONALLY GET AS
HIGH AS AROUND 20 KT DURING THE DAY ON SUNDAY. THERE IS A SIGNAL
FOR SOME VERY LIGHT RAIN OR SPRINKLES TO FALL ON THE TAF SITES
LATER THIS AFTERNOON. HOWEVER, A LACK OF CONFIDENCE AND POSSIBLE
IMPACTS KEPT ANY FORMAL PRECIP MENTION OUT OF THE TAFS. VFR IS
ANTICIPATED THROUGHOUT THE PERIOD.
DOOM
LOT WATCHES/WARNINGS/ADVISORIES
IL...NONE.
IN...NONE.
LM...NONE.
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