588  
FXUS63 KIWX 041035  
AFDIWX  
 
AREA FORECAST DISCUSSION  
NATIONAL WEATHER SERVICE NORTHERN INDIANA  
635 AM EDT THU SEP 4 2025  
   
KEY MESSAGES  
 
- HIGHS ONLY IN THE 60S TO AROUND 70 TODAY THROUGH SATURDAY.  
BRIEFLY WARMER SOUTH OF US 24 ON FRIDAY IN THE LOW TO MID  
70S.  
 
- BREEZY ON FRIDAY WITH GUSTS UP TO 30 TO 35 MPH.  
 
- MAINLY DRY OVER THE NEXT 7 DAYS.  
 
- THERE IS A HIGH SWIM RISK FOR SOUTHERN LAKE MICHIGAN BEACHES  
IN LA PORTE, IN AND BERRIEN COUNTY, MI TODAY. A BEACH HAZARDS  
STATEMENT IS IN EFFECT UNTIL 5 PM ET/4 PM CT. HAZARDOUS  
SWIMMING CONDITIONS PERSIST INTO FRIDAY AND SATURDAY AS WELL.  
 
 
   
DISCUSSION  
 
ISSUED AT 254 AM EDT THU SEP 4 2025  
 
AN AREA OF LOW PRESSURE IS CURRENTLY LOCATED NEAR THE HUDSON  
BAY WITH THE ATTENDANT SURFACE COLD FRONT DRAPED ACROSS THE FAR  
SOUTHEAST PORTION OF OUR FORECAST AREA. EXPECT LIGHT TO MODERATE  
RAIN TO CONTINUE OVER THE NEXT FEW HOURS, ESPECIALLY SOUTH OF  
THE US 24 CORRIDOR. RAIN WILL COME TO AN END BY DAYBREAK.  
TODAY, A MUCH COOLER DAY IS ANTICIPATED WITH HIGHS ONLY IN THE  
MID TO UPPER 60S. BEHIND THE COLD FRONT, WINDS WILL SHIFT TO THE  
NORTHWEST AND CAA TODAY WILL RESULT IN A COOL, FALL-LIKE DAY  
ACROSS THE AREA.  
 
WINDS SHIFT TO THE WEST THIS EVENING BEFORE BECOMING SOUTHWEST  
OVERNIGHT. THIS WILL ALLOW FOR A BRIEF PERIOD OF WAA TO OCCUR FRIDAY  
MORNING AND AFTERNOON. THE AFOREMENTIONED AREA OF LOW PRESSURE WILL  
STILL BE SPINNING OVER NORTHERN ONTARIO FRIDAY, WITH A TIGHT  
PRESSURE GRADIENT DEVELOPING ACROSS THE GREAT LAKES AS THE LOW  
DEEPENS. IN THE UPPER LEVELS, A STRONG JET STREAK OVER THE GREAT  
LAKES WILL PIVOT THROUGH. THERE IS STILL UNCERTAINTY ON EXACTLY HOW  
STRONG WINDS COULD GET DEPENDENT ON THE LOCATION OF THE LOW AND HOW  
MUCH CLEARING OCCURS TO MIX STRONGER WIND GUSTS TO THE SURFACE. FOR  
NOW, HAVE KEPT A SIMILAR FORECAST TO THE PREVIOUS SHIFT WITH GUSTS  
AS HIGH AS 30 TO 35 MPH DURING THE DAY FRIDAY. ALONG AND SOUTH OF  
THE US 24 CORRIDOR HAS THE BEST CHANCES OF HAVING MIXING OCCUR.  
SKIES STAY MOSTLY CLEAR OUT AHEAD OF THE COLD FRONT ALONG AND  
SOUTH OF THE US 24 CORRIDOR THROUGH FRIDAY AFTERNOON, WHICH WILL  
ALSO BOOST HIGHS IN THE LOW TO MID 70S FRIDAY; THE REST OF THE  
AREA WILL SEE HIGHS IN THE MID 60S TO NEAR 70 FRIDAY AS THE COLD  
FRONT WILL SWEEP THROUGH BEFORE THE PEAK DIURNAL HEATING  
OCCURS.  
 
THIS SECOND COLD FRONT WILL REINSTATE NORTHWEST FLOW AND REINFORCE  
COOLER THAN NORMAL TEMPERATURES THROUGH THE WEEKEND. HIGHS WILL ONLY  
REACH THE UPPER 60S TO LOW 70S DEGREES BOTH DAYS. AS SURFACE HIGH  
BUILDS ACROSS THE REGION, DRY AND COOLER CONDITIONS STICK AROUND  
THROUGH EARLY NEXT WEEK. TEMPERATURES WILL GRADUALLY MODERATE BACK  
TOWARDS SEASONABLE LEVELS BY MID TO LATE IN THE WEEK.  
 
ADDITIONALLY, BREEZY NORTHWEST WINDS TODAY WILL GENERATE HIGH WAVES  
OVER LAKE MICHIGAN. MINOR SEICHE ACTIVITY HAS BEEN OBSERVED IN THE  
PAST 12 HOURS AT HOLLAND, MI AND CALUMET HARBOR, IL, WHICH WILL  
AID IN INCREASING WAVE HEIGHTS THROUGH THE MORNING HOURS. A  
BEACH HAZARDS STATEMENT IS IN EFFECT THROUGH 5 PM ET/4 PM CT  
THURSDAY. THERE IS A HIGH SWIM RISK FOR BOTH BERRIEN COUNTY, MI  
AND LA PORTE COUNTY, IN BEACHES TODAY WITH WAVES EXPECTED IN THE  
4 TO 8 FEET RANGE. STAY OUT OF THE WATER AND STAY OFF OF  
PIERS/BREAKWALLS! STRONG RIP AND STRUCTURAL CURRENTS ARE  
EXPECTED IN ADDITION TO THE HIGH WAVE ACTION. WAVES BRIEFLY  
SUBSIDE OVERNIGHT WITH WAA BUT WAVES BUILD AGAIN FOLLOWING THE  
PASSAGE OF FRIDAY'S COLD FRONT. HAZARDOUS SWIMMING CONDITIONS  
DEVELOP AGAIN FRIDAY AND SATURDAY SO ADDITIONAL HEADLINES WILL  
LIKELY BE NEEDED IN THE NEXT 1-2 FORECAST ISSUANCES.  
 
 
   
AVIATION /12Z TAFS THROUGH 12Z FRIDAY/  
 
ISSUED AT 632 AM EDT THU SEP 4 2025  
 
LIGHT LAKE EFFECT RAIN SHOWERS MAY GRAZE KSBN OVER THE NEXT  
COUPLE OF HOURS. CIGS/VSBYS SO FAR HAVE REMAINED VFR, BUT COULD  
BE A BRIEF DROP TO MVFR IF ONE MANAGES TO PASS OVER THE SITE.  
DURATION AND LOW CONFIDENCE IN IMPACTS WARRANTS MAINTAINING VFR  
CONDITIONS. WINDS WILL PICK UP SOME LATER THIS MORNING INTO THE  
AFTERNOON WITH GUSTS OF 20 TO MAYBE 25 KTS.  
 
 
   
IWX WATCHES/WARNINGS/ADVISORIES  
 
IN...BEACH HAZARDS STATEMENT UNTIL 4 PM CDT THIS AFTERNOON FOR  
INZ103.  
OH...NONE.  
MI...BEACH HAZARDS STATEMENT UNTIL 5 PM EDT THIS AFTERNOON FOR  
MIZ177-277.  
MARINE...SMALL CRAFT ADVISORY UNTIL 5 PM EDT THIS AFTERNOON FOR LMZ043-  
046.  
GALE WARNING FROM 2 AM TO 11 AM EDT FRIDAY FOR LMZ043-046.  
 
 
 
 
 
DISCUSSION...JOHNSON  
AVIATION...FISHER  
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