567
FXUS63 KIWX 071746
AFDIWX

Area Forecast Discussion
National Weather Service Northern Indiana
146 PM EDT Mon Sep 7 2026

.KEY MESSAGES...

- High temperatures in the low-80s today and trending slightly
warmer Tuesday and Wednesday.

- There is a 40% to 60% chance of showers and thunderstorms
Wednesday through early Thursday morning.

- There is a Moderate Swim Risk along the beaches of southeastern
Lake Michigan Wednesday and Thursday.

&&

.DISCUSSION...
Issued at 145 PM EDT Mon Sep 7 2026

Main focus over the next couple of days will be flattening of upper
level ridge in response to an approaching, somewhat deamplifying
wave. Signals past several days have been a line of showers and
storms forming on the sfc front to the NW Tuesday afternoon and
progressing east Tuesday night, most likely weakening as it arrives
in our NW counties towards Wed AM, with potential for renewed
development in the afternoon in the SE half or so of the area.
Moisture (Dewpoints upper 60s to maybe low 70s), decent instability
(SBCAPE 1000-2000 J/KG) and at least minimally favorable shear
(around 30 kts) will exist Wed afternoon/eve, resulting in SPC
introducing a Marginal Risk of severe storms in SE areas. That being
said, several models have sort of backed off on coverage Tuesday
night and also location of redevelopment Wed afternoon/eve. Cloud
cover Wednesday will play a huge role in what unfolds across our
area both with convective potential and eventual afternoon highs.
Given the items noted, it is hard to buy into model blend of
categorical pops far NW Wed AM and SE Wed night with previous shift
capping pops in the likely range (more reasonable but possibly still
overdone). Did cap pops Wed AM to likely, but for now will leave the
small sliver of cat pops in my far SE Wed night.

The initial front/pre-frontal trough will weaken with time Wed
night into Thur and stall or wash out with another disturbance
arriving later Thu into Thu night to finally push out the lingering
low level moisture and allow a return to more seasonable
temperatures as the west to east elongated upper ridge is suppressed
across the southern half of the US through the weekend. A deeper
trough enters the central US for the start of the work week which
may bring chances for showers and storms as well as warmer
temps.

&&

.AVIATION /18Z TAFS THROUGH 18Z TUESDAY/...
Issued at 145 PM EDT Mon Sep 7 2026

Warm advection ensues Tuesday morning after overnight cold advection
meaning high to mid clouds return tonight into Tuesday. As a result,
east winds veer southerly Tuesday morning and the high clouds should
restrict fog development from radiational cooling overnight. Winds
are still weaker than 10 kts with little if any gusts.

&&

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

&&

$$

DISCUSSION...Fisher
AVIATION...Roller