126
FXUS63 KIWX 101734
AFDIWX

Area Forecast Discussion
National Weather Service Northern Indiana
134 PM EDT Thu Jul 10 2025

.KEY MESSAGES...

- Strongest storms Friday afternoon and evening when SPC has a
  marginal severe storm risk.

- More storms are possible Saturday afternoon and evening. These
  storms are not expected to become severe.

- Very warm afternoon highs near 90 Friday and Saturday with
  heat indices in the 90s.

- There is a Moderate Swim Risk for southeast Lake Michigan
  beaches this morning.

&&

.DISCUSSION...
Issued at 258 AM EDT Thu Jul 10 2025

Patchy ground fog had developed overnight mainly over northeast
Indiana. Visibilities were extremely variable with the lowest
values at this time at GWB (1/2SM FG). A weak cold front had
moved southeast and had become quite diffuse from about TOL to
GGP. The front should wash out after daybreak with warm
temperatures this afternoon. An isolated storm is possible,
mainly in the favored convective time of 19Z to 01Z. Much better
chances for storms are ahead Friday and Saturday. Thunderstorms
are likely to fire on the weak front and also on old outflow
boundaries that have made it into the area on Friday. The
environment will become very unstable Friday afternoon with
basically a low shear/high CAPE setting. GFS CAPES reach as high
as 3500 J/Kg. Locally heavy rains and strong gusty winds are
possible. Precipitable water values will be hovering close to
anomalously high values of 2.0 inches. Strong storms are
possible again Saturday, depending how unstable conditions can
become and where boundaries are located. Otherwise, very warm
and humid conditions will develop during the afternoons of today
through Saturday. Heat indices are expected to rise will into
the 90s Friday and close to 100F Saturday afternoon.

&&

.AVIATION /18Z TAFS THROUGH 18Z FRIDAY/...
Issued at 122 PM EDT Thu Jul 10 2025

VFR conditions in the near term with wind less than 10 knots
thanks to high pressure centered over the Upper Great Lakes. A
mesoscale low is swirling over southeast MN, northeast IA, as
of this writing. This feature is forecast to ignite
thunderstorms near the MS River late this afternoon. Latest high
resolution guidance has some concensus that this decaying line
of showers, possibly a thunderstorm, arrives near KSBN after
09z. Confidence is medium at best. Forecast soundings show some
mid-level capping which favors the anticipated weakening trend.
Weak upper-level flow makes the eastward progress of this
feature uncertain. However, high confidence KFWA avoids storms
in the early morning. Instead, a leftover outflow boundary may
be the focus for isolated thunderstorms Friday afternoon, just
beyond this TAF period.

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

&&

$$

DISCUSSION...Skipper
AVIATION...Brown