FXUS63 KIWX 230707 AFDIWX Area Forecast Discussion National Weather Service Northern Indiana 307 AM EDT Sun Aug 23 2026 .KEY MESSAGES... - Hazardous swimming conditions are expected on Lake MI beaches along Berrien Co, MI and La Porte County, IN today. Dangerous waves and currents are expected. Monitor the beach forecast for updates. - Chances (20-30%) for rain showers today, with partly cloudy skies and gusty northwest winds. Highs in the low-mid 70s. - Dry tonight into Wednesday morning. Chances for showers and thunderstorms (30-60%) return Wednesday afternoon and persist into Thursday. Highs in the 70s, low 80s. && .DISCUSSION... Issued at 306 AM EDT Sun Aug 23 2026 The 500mb low hovering over northern Ontario will deepen and shift southward into the Lake Huron/Southern Ontario/Quebec area by late tonight, then lift slowly northeastward through Wednesday along with the corresponding surface low. Our area lingers under cyclonic flow aloft/at the surface through later tonight when surface high pressure builds in beneath an expanding ridge to our west. The upper level ridge builds in more broadly on Tuesday. A shortwave pinwheeling around the closed low moves through this afternoon/eve along with a surface trough, which will re-invigorate the stronger northwest wind gusts and wave activity on Lake MI (thus beach hazards statement/small craft remain in place until this evening despite the lull overnight/early AM). It will also bring us the potential for rain showers where deeper moisture remains and we get some afternoon instability (perhaps a little enhancement from cooler air over Lake MI). Have chances around 20-30 percent. With cooler 850mb temps (7-10C) high temps this afternoon will primarily be in the low to mid 70s, warmest east of I 69. Lows tonight will be in the low to mid 50s. Dry conditions persist from tonight into Wednesday morning as a dampening upper level ridge moves in over the Great Lakes. Highs will be in the 70s, low 80s. Lows will be in the 50s. Another upper level trough moves through the Great Lakes Wednesday afternoon into Thursday night, bringing a surface low through northern Ontario into Hudson/James Bay. A cold front will move west to east across our CWA Wed afternoon into Thu, bringing us chances (30-60%) for showers and thunderstorms. Beyond that period, the upper low lingers over Hudson Bay into Saturday, eventually moving northeast through the weekend. Flow over our area becomes more zonal in this time, with potential precipitation chances with each shortwave rippling through. Confidence wasn't high enough to have any pops for Friday/Saturday, but on Sunday we see a stronger wave move in so have 20-30 percent chances added in. Temperatures remain in the mid-upper 70s, low 80s through the period. && .AVIATION /06Z TAFS THROUGH 06Z MONDAY/... Issued at 151 AM EDT Sun Aug 23 2026 Predominantly VFR conditions at the terminals this period, with MVFR ceilings/vis possible during shower activity this morning (KSBN) and possibly this afternoon (KFWA). Some of guidance hinting at some BR development at KFWA early but left out for now given winds are slightly stronger than models depict. Stronger W-NW winds return this afternoon, with gusts up to around 20-25 knots possible. Confidence in shower activity impact either terminal is fairly is low-a lot of the guidance is pretty widely scattered in terms of areal coverage. However, felt confident to at least put a mention for KSBN given upstream showers over Lake MI with incoming trough. Added a prob30 to KFWA for later this afternoon. && .IWX WATCHES/WARNINGS/ADVISORIES... IN...Beach Hazards Statement through this evening for INZ103. OH...None. MI...Beach Hazards Statement through this evening for MIZ177-277. MARINE...Small Craft Advisory until 11 PM EDT this evening for LMZ043- 046. && $$ DISCUSSION...MCD AVIATION...MCD