570
FXUS63 KIWX 011853
AFDIWX

Area Forecast Discussion
National Weather Service Northern Indiana
253 PM EDT Mon Sep 1 2025

.KEY MESSAGES...

- Large diurnal swings (daily temperature ranges) are expected
  through Wednesday with highs near 80 and lows well down into
  the 50s.

- A strong cold front will bring showers and isolated thunderstorms
  Wednesday afternoon through early Thursday,

- Highs only in the 60s Thursday and Friday with chilly lows well
  down into the 40s.

- There is a High Swim Risk for both La Porte County, IN and
  Berrien County, MI on Thursday.

&&

.DISCUSSION...
Issued at 229 PM EDT Mon Sep 1 2025

Cool and dry weather persisted over a large part of the region
associated with an expansive high pressure ridge from New England to
the High Plains. The airmass will attempt to modify ahead of a cold
front that is expected to arrive Thursday night. The latest model
runs support chances for showers and isolated thunderstorms in
about a 24 hour window from Wednesday 18Z (2pm EDT) to Thursday
18Z (2 pm EDT) with the passage of the front. Ahead of this front,
large diurnal temperature ranges will persist with highs around
80 and lows from 50 to 55.

Showers and isolated storms are expected with the passage of the
front late Wednesday and Wednesday night. Severe storms are not
forecast given very limited moisture and instability, and
overall relatively weak and limited dynamics. Mainly dry and
cool weather is ahead from late Thursday through the weekend
with highs in the upper 60s to lower 70s.

&&

.AVIATION /18Z TAFS THROUGH 18Z TUESDAY/...
Issued at 1252 PM EDT Mon Sep 1 2025

Rex block pattern continues a forecast persistence mode with the 18Z
TAFs. An expansive low level anticyclone tied to a broad northern
stream upper ridge will continue to allow a weak easterly flow
regime to persist across northern Indiana. With a few degrees of
warming today compared to yesterday, some potential exists for a
weak lake breeze to impact KSBN late in the afternoon or early
evening with a brief period of northeast winds less than 10 knots
possible. Some patchy shallow fog is also possible early Tuesday
morning, but expectation is that this would be mainly for outlying
rural locations and will continue to omit mention from terminal
forecast.

&&

.IWX WATCHES/WARNINGS/ADVISORIES...
IN...None.
OH...None.
MI...None.
MARINE...None.

&&

$$

DISCUSSION...Skipper
AVIATION...Marsili