366
FXUS63 KIWX 041540
AFDIWX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE NORTHERN INDIANA
1140 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 /18Z TAFS THROUGH 18Z FRIDAY/
ISSUED AT 1140 AM EDT THU SEP 4 2025
DIURNAL POST-FRONTAL CU FIELD THIS AFTERNOON SHOULD REMAIN SCT-
BKN AND MAINLY LOW VFR. VFR/DRY OTHERWISE THROUGH THE PERIOD
WITH A ~40 KT LLJ KICKING IN TONIGHT IN RESPONSE TO A VIGOROUS
SHORTWAVE PIVOTING EAST THROUGH THE GREAT LAKES. SHOWERS WILL
BYPASS NORTH, WITH GUSTS TO NEAR 30 KNOTS EXPECTED ONCE DIURNAL
HEATING COMMENCES MID MORNING THROUGH THE EARLY AFTERNOON ON
FRIDAY.
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...STEINWEDEL
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