772
FXUS63 KIWX 192309
AFDIWX

Area Forecast Discussion
National Weather Service Northern Indiana
709 PM EDT Sat Sep 19 2026

.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 144 PM EDT Sat Sep 19 2026

Active weather will continue through the weekend and periods of
rain will remain possible through at least midweek. A quasi-
stationary frontal boundary that is currently located just south
of the forecast area will be the focus for moderate to heavy
rain over the next 24 hours as a series of shortwaves move over
the region in near zonal flow. We are currently experiencing a
general lull in precip coverage/chances which will last through
mid evening before the next upper level impulse arrives. Another
shortwave and theta-e surge is expected tonight, focusing
locally heavy rain and embedded thunder mainly along and north
of the US 30 corridor. Another round then Sunday afternoon/evening
is 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 very moist 1.8-2.2 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 there are lower probabilities to the south, though
any additional rain in areas just south of Fort Wayne will
further exacerbate ongoing high water issues.

Drier conditions are forecast for Monday, although a weak
shortwave will move through Monday afternoon bringing some light
rain showers, mainly south of US 30. Then, a slow moving
through that is currently situated over the northern Rockies
will make its way eastward over the next several days and
finally move into the Great Lakes on Tuesday. As the low crosses
the area going into Wednesday, periodic showers will continue,
and possibly persist into Thursday and Friday. High pressure
ridging will move in behind this system for mild and dry weather
next weekend.

&&

.AVIATION /00Z TAFS THROUGH 00Z MONDAY/...
Issued at 709 PM EDT Sat Sep 19 2026

An area of rain is approaching KSBN from the west with lightning
confined to far western IL. This activity will gradually track
east through the critical TAF period. With a narrow corridor of
elevated instability at KSBN during the late night hours, have
maintained TS there. This instability axis struggles to progress
into KFWA, so, remain TS free there; confidence is low. Heading
toward daybreak Sunday, showers are likely most widespread
toward KSBN before becoming more focused toward KFWA. A period
of dry weather is anticipated just beyond this TAF period as
the low pressure system responsible drops south.

&&

.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.

&&

$$

DISCUSSION...Cobb
AVIATION...Brown