textproduct: Northern Indiana

KEY MESSAGES

- Several rounds of heavy rain and embedded thunderstorms this weekend. A Flash Flood Watch remains in effect for portions of the forecast area.

- Low chances for scattered rain showers linger into the first half of next week.

- Cooler next week with highs only in the 60s Monday through Wednesday.

DISCUSSION

Issued at 245 AM EDT Sat Sep 19 2026

Well advertised return to periodically wet/stormy wx on track for this weekend as another moisture laden frontal zone sets up over the area. Convectively enhanced mid level perturbations tracking east into the lower Great Lakes, in tandem with several bouts of moisture transport/convergence within nocturnal low level jets, will aid in facilitating these episodes of primarily elevated convection and locally heavy rainfall.

First batch to watch over far southern WI (as of 06z) remains on track to drop southeast through the area this morning into early this afternoon with only minor adjustments made to hourly PoPs and QPF. This activity overall may undergo a slight weakening trending with southeastward progression into areas along and southeast of the US 24 corridor mid morning-early afternoon as it outpaces the low level jet and associated convergence/MUCAPE axis. Maybe a quarter of an inch southeast to as much an inch or so up near the IN/MI border with this initial round.

A general lull in precip coverage/chances is still anticipated for most of the area mid afternoon through mid evening in between upper level impulses. Available model guidance continues to hint at another shortwave and theta-e surge tonight, focusing locally heavy rain and embedded thunder mainly along and north of the US 30 corridor. Another round then Sunday afternoon/evening possible, especially if/where any boundary layer heating can occur resulting in heavier convective elements. Localized lowland and river/stream flooding, along with flash flooding, remains a concern given the saturated ground and opportunties for training elevated convection in this 1.8-2.0 inch PWAT air mass. No changes were made to the Flood Watch for now (in effect through Sunday morning). Latest guidance does favor areas north of the US 30 corridor for higher probs for 1-3"+ plus. Luckily lower probs to the south, though any additional rain in areas just south of Fort Wayne will further exacerbate ongoing high water issues.

Suppression of the height field and frontal zone expected Monday into Tuesday will result in cool conditions and lower chances for lighter/scattered rain showers. High pressure building into the northern Great Lakes will definitely usher in some cooler and drier low level air within northeasterly flow.

AVIATION /06Z TAFS THROUGH 06Z SUNDAY/

Issued at 1225 AM EDT Sat Sep 19 2026

VFR conditions and east-southeast winds near 10 knots early this morning will give way to a period of showers and embedded storms later this morning into early this afternoon, best chances for more significant vis restrictions in heavier showers/storms 13-16z at KSBN and 15-18z at KFWA. A lull in coverage of showers/storms is anticipated behind this initial round this afternoon into early this evening with cigs in the MVFR to low VFR category.

IWX WATCHES/WARNINGS/ADVISORIES

IN...Flood Watch through Sunday morning for INZ005>009-012-014-015- 017-018-023>027-032>034-103-104-116-203-204-216. OH...Flood Watch through Sunday morning for OHZ015-024. MI...Flood Watch through Sunday morning for MIZ078>080-177-277. MARINE...None.