770 FXUS63 KIWX 050555 AFDIWXArea Forecast Discussion National Weather Service Northern Indiana 155 AM EDT Fri Sep 5 2025
.KEY MESSAGES...
- Breezy and briefly warmer on Friday with westerly gusts of 25 to 35 mph.
- Mainly dry over the next 7 days.
- Cool temperatures this weekend into early next week.
- Dangerous swimming conditions expected for Lake Michigan beaches through Saturday.
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.DISCUSSION... Issued at 206 PM EDT Thu Sep 4 2025
A compact/robust shortwave and deepening surface low pressure center will slingshot east through the northern Great Lakes tonight into Friday, eventually getting absorbed into an Ontario upper low later Friday-Friday night. Any warm advection precipitation should miss north given the track, with the main impact locally being a ramping pre-frontal kinematic field later tonight into Friday morning. HREF guidance suggests a ~40 kt LLJ during this time which could promote brief gustier west winds (30-40 mph) mid morning through early afternoon as greater mixing commences. The low level wind field does diminish Friday afternoon as the trailing sfc trough tracks through, though CAA and increased mixing depths will still keep things gusty. Models do hint a brief FGEN flare up over southern portions of the forecast Friday afternoon. The sub 700 mb air is very dry however suggesting virga/sprinkles at worst. Timing of the front should favor highs ranging from the mid 60s northwest to the upper 70s southeast otherwise.
Upper troughing will linger over the region into this weekend with cooler weather persisting. Several small amplitude impulses will swing through in this regime with non-zero chances for a few sprinkles or light showers, best chances (10%) in lower MI thanks to some Lake MI moisture flux Saturday night into Sunday. Given the weak nature to these waves, and the overall dearth of moisture, will continue with a dry forecast for most through the weekend. Surface high pressure then follows in by early next week with temperatures on a gradual warming trend.
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.AVIATION /06Z TAFS THROUGH 06Z SATURDAY/... Issued at 155 AM EDT Fri Sep 5 2025
A cold front, extending from SW Wisconsin to NW Missouri will sweep east, reaching KSBN either side of 14Z and a few hours later at KFWA. Area of mid clouds was along and ahead of the front with some sprinkles/light showers which have shown an overall decreasing trend. Can`t rule out a brief sprinkle or light shower at KSBN later tonight, but not worth adding at this point given no flight impacts. More noticeable will be increasing west to northwest winds near and behind the front as increasing pressure gradient and strong mixing of winds aloft allow for gusts of 35 to 30 kts at both sites during peak heating.
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.IWX WATCHES/WARNINGS/ADVISORIES... IN...Beach Hazards Statement from 4 AM CDT early this morning through late tonight for INZ103. OH...None. MI...Beach Hazards Statement from 5 AM EDT early this morning through late tonight for MIZ177-277. MARINE...Gale Warning until 11 AM EDT this morning for LMZ043-046.
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DISCUSSION...Steinwedel AVIATION...Fisher
NWS IWX Office Area Forecast Discussion