551
FXUS63 KIWX 042332
AFDIWX

Area Forecast Discussion
National Weather Service Northern Indiana
732 PM EDT Mon Aug 4 2025

.KEY MESSAGES...

- Temperatures gradually moderate to above normal this week. By
  late week and this weekend, very warm and humid conditions
  return.

- There is a slight chance (20%) for isolated/afternoon showers
  and storms for areas mainly south of US 30 on Tuesday, and
  along and east of US 31 on Wednesday.

&&

.DISCUSSION...
Issued at 206 PM EDT Mon Aug 4 2025

A slow moving mid level trough over the Mid MS Valley will meander
eastward through the OH Valley later tonight through Wednesday. This
will allow an elevated moisture gradient over the OH Valley to
slowly stream north into the local area. Sfc dewpoints will also
respond with weak instability developing over southern zones on
Tuesday, and over mainly east-southeast zones by peak heating on
Wednesday. Overall forcing is weak however with lingering dry
easterly flow in the low levels. Continued to cover with a 10-20%
type PoP with this feature given these limitations. Seasonably warm
and humid otherwise through the middle of the week.

Models continue to agree in upper ridging dominating for the second
half of the week into the weekend with building heat and humidity,
along with mainly dry conditions given a strengthening cap.

&&

.AVIATION /00Z TAFS THROUGH 00Z WEDNESDAY/...
Issued at 728 PM EDT Mon Aug 4 2025

Another period of quiet aviation weather is expected this
forecast valid period. A weak mid/upper level disturbance will
continue to drift east across the Ohio Valley tonight into
Tuesday. Convection to the south of the area may help to
slightly enhanced low level easterly flow across the local area
which should keep richer low level moisture confined to the
south/southeast of northern Indiana. This should result in
limited instability profiles to work with once again on Tuesday
with terminals expected to remain dry. Easterly flow persists
into Tuesday, although low level height gradient may be weak
enough to support a weak lake breeze moving into KSBN vicinity
late Tuesday afternoon.

&&

.IWX WATCHES/WARNINGS/ADVISORIES...
IN...Air Quality Alert from midnight EDT /11 PM CDT/ tonight to
     midnight EDT /11 PM CDT/ Tuesday night for INZ005>009-
     012>015-017-018-022>027-032>034-103-104-116-203-204-216.
OH...None.
MI...Air Quality Alert until midnight EDT Tuesday night for
     MIZ078>081-177-277.
MARINE...None.

&&

$$

DISCUSSION...Steinwedel
AVIATION...Marsili