309
FXUS63 KIWX 301748
AFDIWX

Area Forecast Discussion
National Weather Service Northern Indiana
148 PM EDT Mon Jun 30 2025

.KEY MESSAGES...

- Numerous showers and storms this afternoon and evening. A few storms
  could be strong to severe with damaging winds and heavy
  rainfall.

- Dry, seasonable, and less humid by mid to late in the week.

- Hot and humid by the weekend with chances for rain/storms.

&&

.DISCUSSION...
Issued at 146 PM EDT Mon Jun 30 2025

A cold front is located near Milwaukee extending southeast
towards Kansas City, and it will slowly move east this afternoon
and evening. Ahead of the front, destabilization is already
occurring across our forecast area. A growing cumulus field is
evident on visible satellite imagery; Additionally,
temperatures are already in the low to mid 80s and dewpoints are
in the low 70s. Amidst this hot and humid airmass, scattered
multicell clusters of showers and storms are ongoing east of IN
15, fueled by a lake breeze coming off of Lake Michigan.
Additional storms will be possible later this evening after
sunset along the cold front. Much like yesterday, it will be
feast or famine for storms. Some locations may get nothing while
others get several inches of rain in a short amount of time.
The Storm Prediction Center has maintained the Marginal Risk
(level 1 of 5) for our entire forecast area, meaning a few
storms could be strong to severe today. The setup for severe
weather appears fairly unimpressive as there is ample
instability for storms to work with (2500-3000 J/kg SBCAPE), but
no source of lift (until the front arrives) and little to no
shear in place as vertical wind profiles are unidirectional out
of the west-southwest. Confidence in severe weather occurring is
low. Inverted v soundings from the HREF and NAM show some
possibility for localized microbursts/damaging winds should
strong to severe storms develop. There is also a Marginal Risk
(level 1 of 4) for localized flash flooding per WPC. Should
storms get going along the lake breeze and dive southward, some
backbuilding will be possible with low level low from the west
parallel to the boundary and slow Corfidi upshear winds.
Precipitation rates should be efficient today given long, skinny
CAPE profiles, a deep warm cloud layer, and PWATs above the
75th percentile of 1.5-1.75".

July will start dry and seasonable as an upper level ridge
expands across the Central Plains and moves eastward. Tuesday
through Friday will be mainly dry as surface high pressure
builds across much of the eastern CONUS. As the upper level
pattern becomes more amplified over the Midwest Saturday and
Sunday, hot and humid conditions return. Highs in the low 90s
return with heat indices in the mid 90s. Some diurnal chances
for rain/storms may be possible for the 4th of July weekend into
early next week.


&&

.AVIATION /12Z TAFS THROUGH 12Z TUESDAY/...
Issued at 611 AM EDT Mon Jun 30 2025

Cloudiness began to scatter out in the west during the mid morning
and that has allowed for some instability to form. Models are little
inconsistent on where storms will be during the afternoon and
evening hours, but still feel confident enough to keep a mention of
showers and storms at FWA this afternoon. We`ll then have to
watch the arrival of a cold front after 00z. Given how much
debris clouds have been across the area this morning and how
late it is at night, would expect that this should just stay
showers. Some MVFR flight conditions will be possible from
those showers as they move through. The cold front moves
through and brings a cooler and drier airmass overnight into
Tuesday, but at this point the BR/fog chance looks low. Winds
are still expected to stay at or less than 10 kts with west
southwest winds veering more northwesterly by the end of the
period.

 &&

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

&&

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

&&

$$

DISCUSSION...Johnson
AVIATION...Roller