778
FXUS63 KIWX 031807
AFDIWX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE NORTHERN INDIANA
207 PM EDT WED SEP 3 2025
KEY MESSAGES
- A PERIOD OF RAIN SHOWERS EXPECTED FROM NORTHWEST TO SOUTHEAST
LATE THIS AFTERNOON INTO EARLY THURSDAY MORNING. EMBEDDED,
NON-SEVERE, THUNDERSTORMS ARE ALSO POSSIBLE.
- ANOTHER STRETCH OF BELOW NORMAL TEMPERATURES THURSDAY THROUGH THIS
WEEKEND.
- THERE IS A HIGH SWIM RISK FOR SOUTHERN LAKE MICHIGAN BEACHES
IN LA PORTE, IN AND BERRIEN COUNTY, MI ON THURSDAY. HAZARDOUS
SWIMMING CONDITIONS PERSIST INTO FRIDAY AND SATURDAY AS WELL.
DISCUSSION
ISSUED AT 207 PM EDT WED SEP 3 2025
A STRONG COLD FRONT, CURRENTLY NEAR THE WI/IL BORDER AND LAKE MI,
WILL SWEEP SOUTHEAST THROUGH THE LOCAL AREA TONIGHT. SCATTERED
PRE-FRONTAL SHOWERS, AND PERHAPS A FEW EMBEDDED THUNDERSTORMS,
WILL REMAIN POSSIBLE THIS AFTERNOON ACROSS MAINLY NW IN AND SW
MI ON THE LEADING EDGE OF THE THETA-E GRADIENT. MORE WIDESPREAD
SHOWER ACTIVITY THEN ACCOMPANIES THE MAIN FRONT FROM NW TO SE
THIS EVENING INTO EARLY THURSDAY AS CVA AND UPPER DIVERGENCE
OVERSPREAD THE FRONTAL SLOPE WITH ADEQUATE MOISTURE TO WORK
WITH. ROBUST POST-FRONTAL COLD ADVECTION THEN BRINGS UNSEASONABLY
COOL WX BACK INTO THE PICTURE TONIGHT INTO THURSDAY. A FEW LAKE
EFFECT SPRINKLES OR SHOWERS CANNOT BE RULED OUT LATER TONIGHT
INTO THURSDAY MORNING IN NW/NC IN AND SW MI AS THIS COLDER AIR
SURGES OVER WARMER LAKE MI WATERS. QUICK DRYING WITH FLOW
TRAJECTORIES BACKING MORE WESTERLY FAVOR LOWER-END POPS (10-
20%). STRATOCU SHOULD SCATTER OUT DURING THE DAY THURSDAY
OTHERWISE WITH HIGHS ONLY REACHING THE MID-UPPER 60S.
THE NEXT SHORTWAVE TROUGH AND ASSOCIATED COLD FRONT WILL TAKE A
SIMILAR PATH AS IT PIVOTS THROUGH THE WESTERN AND SOUTHERN
PERIPHERY OF AN ONTARIO UPPER LOW THROUGH THE UPPER MIDWEST AND
GREAT LAKES. THE BULK OF ANY WARM ADVECTION PRECIPITATION MAINLY
BYPASSES NORTH LATE THURSDAY NIGHT, WITH SHOWER CHANCES APPEARING
LOW ALONG THE TRAILING COLD FRONT ON FRIDAY GIVEN A LESS FAVORABLE
MOISTURE PROFILE AND EXIT OF DEEPER ASCENT. THE MAIN IMPACT WILL BE
THE SOMEWHAT BREEZY CONDITIONS ON FRIDAY WITH THE FROPA AS SFC LOW
PRESSURE EMERGES OVER THE NORTHERN GREAT LAKES, WITH CAA AND
STEEPENING LOW LEVEL LAPSE RATES LIKELY SUPPORTING A FEW GUSTS UP TO
NEAR 25-30 MPH.
HIGH PRESSURE DOMINATES THIS WEEKEND INTO EARLY NEXT WEEK ON THE
BACKSIDE OF THE EXITING LONGWAVE TROUGH WITH COOL WEEKEND TEMPS
(HIGHS MID 60S TO LOW 70S) WARMING BACK UP TO NEAR 80F BY THE MIDDLE
OF NEXT WEEK.
AVIATION /18Z TAFS THROUGH 18Z THURSDAY/
ISSUED AT 102 PM EDT WED SEP 3 2025
SHOWERS OVER NORTHEAST IL WERE APPROACHING NORTHERN INDIANA AT
THE START OF THE TAF PERIOD. VERY FEW RAINFALL AMOUNTS WITH THIS
SYSTEM WERE OVER 0.05" ACCORDING TO NUMEROUS UPSTREAM MESONET
SITES. THE LOWER CEILINGS WERE OVER FAR NORTHERN IL INTO WI.
THESE LOWER CEILINGS WILL EVENTUALLY MAKE IT INTO SBN, ALTHOUGH
AT THIS TIME IT APPEARS CEILINGS BELOW 020 (FUEL ALTERNATES
BELOW 020) SHOULD BE RELATIVELY BRIEF (MAINLY DURING
PRECIPITATION). IT LOOKS LIKE RIGHT NOW, CONDITIONS SHOULD
BECOME VFR BEFORE DAYBREAK.
IWX WATCHES/WARNINGS/ADVISORIES
IN...BEACH HAZARDS STATEMENT FROM 7 PM CDT THIS EVENING THROUGH
THURSDAY AFTERNOON FOR INZ103.
OH...NONE.
MI...BEACH HAZARDS STATEMENT FROM 8 PM EDT THIS EVENING THROUGH
THURSDAY AFTERNOON FOR MIZ177-277.
MARINE...SMALL CRAFT ADVISORY FROM 8 PM THIS EVENING TO 5 PM EDT
THURSDAY FOR LMZ043-046.
DISCUSSION...STEINWEDEL
AVIATION...SKIPPER
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