641
FXUS63 KIWX 251824
AFDIWX

Area Forecast Discussion
National Weather Service Northern Indiana
224 PM EDT Wed Jun 25 2025

.KEY MESSAGES...

- A Heat Advisory remains in effect through 8 PM ET for northern Indiana
  and northwest Ohio. Peak heat indices of 95 to 100 degrees
  are expected today.

- Heat indices Wednesday through Friday will be 90 to 100, with
  the highest values expected along and south of US 30.
  Cumulative effects of long-duration heat will likely cause
  significant impacts.

- Near record warm overnight low temperatures in the low to mid
  70s through the weekend will provide little to no relief from
  the heat, especially for vulnerable populations.

- Numerous showers and thunderstorms are expected this afternoon
  and evening, especially east of US 31. A few storms may become
  strong to severe with damaging winds and heavy rainfall.

&&

.DISCUSSION...
Issued at 222 PM EDT Wed Jun 25 2025

A stalled frontal boundary draped along the Indiana-Michigan
stateline will bring chances for numerous showers and storms this
afternoon and evening. Highs in the upper 80s and dewpoints once
again in the low to mid 70s will result in airmass destabilization
this afternoon. Visible satellite imagery depicts a field of
scattered cumulus clouds across northeast Indiana and northwest
Ohio. While there is a lack of shear, low level lapse rates and
surface based CAPE of 2500+ J/kg will fuel thunderstorm
development this afternoon and evening. Storms have already
initiated in central Indiana as of 2 PM ET, and coverage should
expand across northeast Indiana and northwest Ohio within the
next few hours. The environment is more `capped` (stable) over
the western half of our forecast area today so expect the
shower/storm activity to be greater along and east of US 31.
Because of the slow storm motion and possibility for outflow
boundary interaction, isolated instances of flash flooding will
be possible today. A few storms could become strong to severe;
SPC has our area in a Marginal Risk (level 1 of 5) for severe
weather. Alongside the heavy rain threat, storms could be
capable of producing gusty to damaging winds.

The upper level ridge responsible for the hot and humid conditions
over the past several days persists over much of the eastern
CONUS. A Heat Advisory remains in effect until 8 PM ET today,
although storms (and associated outflow boundaries) may bring
temporary cooling this afternoon/evening. Additional heat
headlines could be needed in the coming days as the hot and
oppressively humid conditions persist. If you consider highs in
the 80s to be a reprieve from the heat, then the next few days
may seem `cooler`. Highs will be in the upper 80s today through
the weekend with lows in the low to mid 70s. While it won`t be
as hot as what we experienced when the Extreme Heat Warning was
in effect earlier in the week, with such muggy, uncomfortable
conditions at night, there will be little relief from the heat
through the weekend. Stay cool and stay hydrated!

The upper level ridge pattern flattens out this week and looks to
potentially break down over the weekend. By early next week, it is
possible we get a reprieve from the heat and temperatures drop back
to near normal levels. Additional rain/storm chances will be
possible over the weekend but confidence is low.

&&

.AVIATION /18Z TAFS THROUGH 18Z THURSDAY/...
Issued at 124 PM EDT Wed Jun 25 2025

Showers and storms are starting to redevelop to the south.
Storms could move up into the FWA airspace around 22Z. Conversely,
SBN may stay dry today, with the latest CAMS now depicting the
best chance for any activity near the terminal to be later this
evening after 03Z, as a weak wave moves in from the northwest.
Outside of any moderate to heavy rain, conditions should remain
VFR at both sites.

&&

.IWX WATCHES/WARNINGS/ADVISORIES...
IN...Heat Advisory until 8 PM EDT /7 PM CDT/ this evening for
     INZ005>009-012>015-017-018-020-022>027-032>034-103-104-
     116-203-204-216.
OH...Heat Advisory until 8 PM EDT this evening for OHZ001-002-004-
     005-015-016-024-025.
MI...None.
MARINE...None.

&&

$$

DISCUSSION...Johnson
AVIATION...Cobb