882
FXUS63 KLOT 082324
AFDLOT
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE CHICAGO/ROMEOVILLE, IL
624 PM CDT TUE SEP 8 2026
KEY MESSAGES
- SHOWERS AND A FEW STORMS WILL MOVE ACROSS THE AREA LATE
TONIGHT THROUGH WEDNESDAY.
- THURSDAY AND FRIDAY LOOK PLEASANT.
- THE NEXT OPPORTUNITIES FOR RAIN WILL ARRIVE THIS WEEKEND AND
CONTINUE INTO EARLY NEXT WEEK.
DISCUSSION
ISSUED AT 120 PM CDT TUE SEP 8 2026
PER A RECENT SUBJECTIVE SURFACE ANALYSES, A 1000 MB SURFACE LOW
PRESSURE SYSTEM IS MOVING ACROSS SOUTHERN MANITOBA WELL TO THE
NORTH OF A SURFACE HIGH PRESSURE SYSTEM PARKED ALONG THE
ATLANTIC COAST. A COLD FRONT EXTENDS SOUTHWARD FROM THE LOW
PRESSURE SYSTEM THROUGH NORTHERN MINNESOTA AND ACROSS THE
CENTRAL PLAINS. AHEAD OF THE FRONT, A BROAD RIBBON OF SOMEWHAT
UNFOCUSED LOW-LEVEL ISENTROPIC ASCENT IS SUPPORTING AREAS OF
SHOWERS AND THUNDERSTORMS FROM NEBRASKA NORTHEASTWARD INTO
CENTRAL WISCONSIN. A POCKET OF RELATIVE DRY AIR IS PRESENT
SOUTHEAST OF THE AXIS OF ISENTROPIC ASCENT, WHICH IS LEADING TO
A PLEASANT DAY ACROSS THE LOWER GREAT LAKES.
THIS AFTERNOON AND EVENING, THE UPPER-LEVEL WAVE CURRENTLY
SUPPORTING SHOWERS AND THUNDERSTORMS ACROSS EASTERN NEBRASKA
WILL SHIFT EASTWARD INTO IOWA AND SUPPORT THE
EXPANSION/INVIGORATION OF THUNDERSTORMS. AFTER SUNSET, RADAR
DATA TO OUR WEST MAY LOOK RATHER INTIMIDATING WITH WHAT MAY BE
SEVERAL CLUSTERS OF STRONG TO SEVERE STORMS MOVING TOWARD THE
MISSISSIPPI RIVER. THANKFULLY, THE ENVIRONMENT EAST OF THE RIVER
WILL BE HOSTILE FOR THUNDERSTORMS TO MAINTAIN THEIR INTENSITY,
SO THE EXPECTATION REMAINS FOR THUNDERSTORM CLUSTERS TO
GRADUALLY WEAKEN AS THEY TRAVERSE EASTWARD INTO NORTHERN
ILLINOIS THROUGH THE NIGHT. PEAK COVERAGE OF ACTIVITY THROUGH
DAYBREAK SHOULD BE MAINLY ALONG AND NORTH OF I-88 AND WEST OF
I-39.
WITH TIME, THE AXIS OF REMNANT SHOWERS WILL DRIFT SOUTHWARD
THROUGH THE AREA FROM SUNRISE THROUGH EARLY AFTERNOON ON
WEDNESDAY. COVERAGE SHOULD THEN DECREASE WITH TIME FROM NORTH TO
SOUTH THROUGH THE AFTERNOON AS A COLD FRONT WORKS ACROSS THE
AREA. REDEVELOPMENT OF THUNDERSTORMS ALONG THE FRONT APPEARS TO
BE A LARGELY UNFAVORED SCENARIO GIVEN LIMITED OPPORTUNITIES FOR
DESTABILIZATION TOMORROW. IN ALL, THE NEXT 24 HOURS DOESN'T LOOK
LIKE A COMPLETE WASHOUT ACROSS OUR AREA WITH MOST AREAS FAVORED
TO GET LESS THAN 0.5" OF AN INCH OF TOTAL RAINFALL.
TEMPERATURES TOMORROW WILL BE MODULATED BY REMNANT SHOWERS AND
CLOUD COVER. WHILE THERE ARE SOME PROSPECTS FOR CLEARING FROM
NORTH TO SOUTH THROUGH THE AFTERNOON, DID OPT TO CUT BACK NBM
TEMPERATURES TO LARGELY ADVERTISE HIGHS AROUND 80 DEGREES.
TOMORROW NIGHT, A FEW WAVES PROPAGATING ALONG THE FRONT SHOULD
ALLOW FOR ADDITIONAL WAVES OF SHOWERS AND A FEW STORMS PRIMARILY
SOUTH OF OUR AREA. DID CUT BACK ON NBM POPS TO PAINT LOW-END
CHANCES (20-40%) FOR SHOWERS NEAR THE US-24 CORRIDOR THROUGH
DAYBREAK THURSDAY.
A SURFACE HIGH PRESSURE SYSTEM WILL SLIDE THROUGH THE REGION
THURSDAY AND FRIDAY LEADING TO QUIESCENT CONDITIONS. BOTH DAYS
WILL BE CHARACTERIZED BY MOSTLY SUNNY SKIES, LIGHT WINDS, AND
HIGHS AROUND 80 DEGREES. A SERIES OF UPPER-LEVEL WAVES MAY
PROVIDE THE OPPORTUNITY FOR A FEW WINDOWS FOR PRECIPITATION THIS
WEEKEND INTO EARLY NEXT WEEK.
BORCHARDT
AVIATION /00Z TAFS THROUGH 06Z THURSDAY/
ISSUED AT 624 PM CDT TUE SEP 8 2026
FORECAST CONCERNS FOR THE TERMINALS...
- PERIOD OF RAIN SHOWERS ALONG A COLD FRONT LATE TONIGHT INTO
WEDNESDAY. AN ISOLATED THUNDERSTORM CANNOT BE RULED OUT
(10-15% CHANCE).
- MVFR CEILINGS AND VISIBILITIES WILL LIKELY ACCOMPANY THE
SHOWERS, BUT OTHERWISE VFR CONDITIONS EXPECTED.
A COLD FRONT CONTINUES TO ADVANCE ACROSS SOUTHERN MN, WESTERN
IA, AND EASTERN NE WITH AN AREA OF SHOWERS AND THUNDERSTORMS
ONGOING AHEAD OF THE FRONT IN IA. THE ONGOING SHOWERS AND
THUNDERSTORMS ARE EXPECTED TO GRADUALLY WEAKEN WITH EASTWARD
EXTENT AS THEY ENCOUNTER DRIER AIR NEAR THE MISSISSIPPI RIVER.
HOWEVER, A LINE OF SCATTERED SHOWERS IS EXPECTED TO MOVE THROUGH
NORTHERN IL AND NORTHWEST IN AFTER MIDNIGHT AND INTO WEDNESDAY
MORNING ALONG THE COLD FRONT AND RESULT IN A PERIOD OF MVFR
CEILINGS AND VISIBILITIES AT THE TERMINALS. WHILE A STRAY RUMBLE
OR TWO OF THUNDER CANNOT BE RULED OUT (10-15% CHANCE), FORECAST
SOUNDINGS CONTINUE TO SHOW VERY LITTLE INSTABILITY LOCALLY SO
SUSPECT THUNDER COVERAGE WILL REMAIN LOW.
THE LINE OF SCATTERED SHOWERS SHOULD PUSH SOUTH OF THE TERMINALS
BY 18Z (15-16Z AT RFD) LEAVING US WITH DRY CONDITIONS FOR THE
REST OF THE TAF PERIOD. THOUGH, A FEW ISOLATED SHOWERS MAY
REDEVELOP SOUTH OF THE KANKAKEE RIVER VALLEY WEDNESDAY
AFTERNOON. AS SHOWERS EXIT CEILINGS WILL IMPROVE BACK TO VFR
WITH CLOUD BASES GENERALLY AROUND 6000-10000 FT. WINDS WILL ALSO
CONTINUE TO TURN MORE NORTHWESTERLY BEHIND THE SHOWERS WITH
SPEEDS INITIALLY AROUND 8-10 KTS BEFORE EASING TO AROUND 5 KTS
AFTER SUNSET WEDNESDAY EVENING.
YACK
LOT WATCHES/WARNINGS/ADVISORIES
IL...NONE.
IN...NONE.
LM...NONE.
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