Area Forecast Discussion
Issued by NWS Northern Indiana
Issued by NWS Northern Indiana
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429 FXUS63 KIWX 302328 AFDIWX Area Forecast Discussion National Weather Service Northern Indiana 728 PM EDT Wed Sep 30 2026 .KEY MESSAGES... - Showers will persist across much of the area into this evening, before weakening. Greatest chances (40-80%) will remain northwest of US-69. - Window of dry weather likely late tonight into Thursday morning. Chances for showers (50-90%) and an isolated thunderstorms return Thursday afternoon into Thursday night. Locally heavy rain is possible, but overall flood concerns appear low at this time. - Dry conditions are expected this weekend into early next week, with highs in the 60s, low 70s (warmest further south). Overnight lows will drop into the 40s. && .DISCUSSION... Issued at 204 PM EDT Wed Sep 30 2026 Area of weak isentropic lift continues advance across the area, with light returns (primarily sprinkles or T amounts of precip) extending east to the I-69 corridor. Steadier rain has remained in NW parts of the area so far. Models have been showing a weakening trend over the past several runs, but given current and upstream radar returns this seems somewhat unrealistic for at least the next several hours. Pops have been continued into early evening with a slow taper from southwest to northeast into the overnight hours. Signs still seem to point towards a small lull in precip late tonight through at least Thursday morning. A closed upper low, currently over the Four Corners area, will fight to work east and eventually northeast along the stubborn SE US ridge. A weaker northern stream trough will dive in as well. The southern stream wave will fill and weaken with NE extent as it is absorbed into the northern stream trough. PWATs will steadily increase through the day Thursday, peaking in the 1.75" to locally 2" range during the afternoon and evening hours ahead of an eastward progressing front. Models indicate some weak surface cyclogenesis that rides along the front mainly Thursday night. All these factors should lead to the best chances for measurable rainfall with average amounts of a half to one inch. A low chance exists for thunderstorms embedded within the area that could aid in locally higher rainfall amounts, but at this point expected rainfall should not cause significant impacts to water levels across the area. Drier air quickly works in from the north Friday as the overall upper flow becomes semi-zonal and deeper moisture is pushed well south. Temperatures this weekend into next week will settle back into the 60s for highs and lows in the 40s with a hint of some upper 30s possibly coming for Tuesday morning. && .AVIATION /00Z TAFS THROUGH 00Z FRIDAY/... Issued at 728 PM EDT Wed Sep 30 2026 Elevated warm/moist air advection into a modest frontal boundary generating widespread light rain despite relatively meager low level moisture profiles. This light rain will likely continue through much of the overnight but conditions should remain primarily VFR. Some MVFR ceilings and vis may be possible at KSBN but confidence is low. This front lifts north slightly Friday morning before returning south again as a cold front late Thursday. MVFR (or lower) ceilings possible at KSBN at the very end of this forecast period and later Thursday night at KFWA. && .IWX WATCHES/WARNINGS/ADVISORIES... IN...None. OH...None. MI...None. MARINE...None. && $$ DISCUSSION...Fisher AVIATION...AGD