Area Forecast Discussion
Issued by NWS Northern Indiana

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032
FXUS63 KIWX 081833
AFDIWX

Area Forecast Discussion
National Weather Service Northern Indiana
233 PM EDT Tue Sep 8 2026

.KEY MESSAGES...

- A warm and more humid airmass will be in place into early
  Thursday. Cloud cover and precipitation may cause large
  variations in temperatures Wednesday.

- There is a 40% to 60% chance of showers and thunderstorms
  Wednesday through early Thursday morning.

- Breaking waves and currents are expected at southeast Lake
  Michigan beaches on Thursday.

- Somewhat cooler and less humid Friday into Monday.

&&

.DISCUSSION...
Issued at 233 PM EDT Tue Sep 8 2026

Low confidence forecast remains through Thursday as models
continue to differ on finer details for temps and precip
chances, especially Wednesday night. Main cold front (much
cooler and less humid air) is located from Minnesota to central
NE and is not expected to arrive till Thursday. Much of our
weather will hinge on pre-frontal troughs, leftover outflow
boundaries and subtle waves resulting in a lot of challenges on
coverage, timing and intensity.

Area of showers and storms has persisted from central IA into
much of WI with only a slow eastward trend. CAMs vary on what
will be left of this area as it enters towards 12Z Wed.
Regardless of what shape it starts, generally expected some
widely sct to sct showers and maybe a few storms to persist in a
somewhat unstable atmosphere. The marginal severe threat keys
in on the afternoon and evening hours when pockets of clearing
could allow for some increased instability to produce some gusty
storms. Overall shear is lacking and lapse rates are rather
unimpressive so any gusts appear to be isolated at most. Even
larger challenges exist where the best instability axis and
lingering boundaries setup Wednesday night into early Thursday.
Overall trend has been moreso into central IN resulting in a
continued southward trend to higher pops. Wasn`t ready to
completely eliminate pops but did blend with previous forecast
to nudge down.

Eventually the main front will arrive Thursday into Thursday
night and usher in an end to any precip and much more
comfortable conditions. The battle will then continue between
the sprawling upper ridge across the SE states and another
deeper trough that will attempt to move in next week. For the
time being, no major swings in temperatures or high precip
chances.

&&

.AVIATION /18Z TAFS THROUGH 18Z WEDNESDAY/...
Issued at 1214 PM EDT Tue Sep 8 2026

Quiet weather continues throughout much of the TAF forecast
period. Southerly winds will be sustained between 5-10 kts
today, highest this evening when they begin to ramp up ahead of
an approaching upstream cold front. Expect southerly winds
between 10-15 kts by daybreak Wednesday with gusts to 20 kts
possible (especially at KFWA). Scattered rain and storms should
arrive around 12Z in far northwest Indiana as the slow moving
cold front moves in. Have added a PROB30 group to KSBN
Wednesday morning given potential for high end MVFR ceilings and
visibilities within any storms. Kept KFWA completely dry as
confidence is high that rain/storms likely do not arrive until
the afternoon there.

&&

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

&&

$$

DISCUSSION...Fisher
AVIATION...Johnson