679
FXUS63 KIWX 100808
AFDIWX

Area Forecast Discussion
National Weather Service Northern Indiana
408 AM 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 /06Z TAFS THROUGH 06Z FRIDAY/...
Issued at 149 AM EDT Thu Jul 10 2025

A weak sfc cool front has become more diffuse across extreme NE
Indiana/NW Ohio early this morning. Residual low level moisture
and near sfc moisture source from yesterday`s rainfall will
likely yield a zone of most preferred fog formation immediately
in the wake of this low level front from west central Indiana
through KFWA vicinity extending into NW Ohio. Have maintained
previous TEMPO IFR mention at KFWA in the 10Z-13Z timeframe,
with a potential of some shorter-lived vsby restrictions at
KSBN. A weak intrusion of low level dry air behind the front
should limit the overall potential at KSBN. Mainly dry
weather is expected through the remainder of the period, with
VFR conditions prevailing.

&&

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

&&

$$

DISCUSSION...Skipper
AVIATION...Marsili