956
FXUS63 KIND 110457
AFDIND

Area Forecast Discussion
National Weather Service Indianapolis IN
1257 AM EDT Fri Sep 11 2026

.KEY MESSAGES...

- Briefly dry then scattered showers and storms return late
  Friday into Saturday

- Cooler Friday with warmer temperatures returning this weekend into
  early next week

&&

.FORECAST UPDATE...
Issued at 1001 PM EDT Thu Sep 10 2026

Late summer set-up tonight will host slow transition into slightly
more pleasant conditions as passing cool frontal zone continues to
drift from the Midwest`s southern tier into the Ohio Valley.  Near
term to feature corresponding scattered showers. While stray thunder
cannot be ruled out, greater potential hazard would be isolated
ponding of low-lying areas, given real-time observation of 0.66
inches at the old Vincennes 4E COOP station which only caught the
edge of the spread`s strongest shower.

Otherwise gradual advance of the southern periphery of surface high
pressure passing to our north...will trend dewpoints downward
through daybreak Friday...although perhaps only discernible drop in
humidity will be along I-70 corridor/north, with upper 50s dewpoints
likely along the Upper Wabash Valley.  Patchy to perhaps even
locally dense fog will be on the table through pre-dawn
hours...especially over southern zones where the combination of
elevated dewpoints and recent light/moderate rainfall will promote
greatest visibility reductions.  Low temperatures by 12Z to range
from 58F in Kokomo to 65F in downtown Indy and 67F in Vincennes.

&&

.DISCUSSION (This evening through Thursday)...
Issued at 230 PM EDT Thu Sep 10 2026

Rest of This Afternoon through Tonight...

The current round of forcing is producing light rain across much of
central Indiana this afternoon. Continued likely PoPs most areas as
this rain moves through.
2
With the northern part of an upper trough axis still moving in,
additional showers may develop later this afternoon, so kept PoPs
going most areas before 00Z. An isolated thunderstorm is possible,
but generally just showers are expected.

The upper trough will weaken this evening, but there looks to be
enough forcing to continue PoPs across the southern half of the area
through the evening.

Patchy fog will develop tonight thanks to the continued moist
atmosphere and light winds. With clouds hanging around, widespread
fog is not currently expected.

Lows tonight will be in the upper 50s north to middle 60s south.

Friday and Saturday...

Surface high pressure will keep much of the area dry through the day
Friday. Friday night into Saturday, a weak upper trough will drift
northeast across the area. Moisture will increase as the upper
trough moves through.

Forcing from the trough will bring some scattered to perhaps
numerous showers to the area, especially south and east where the
better forcing will be. Will go with mainly chance Pops (as best
forcing will be east of the area), with perhaps some low likely PoPs
in the far east.

Highs on Friday will be mainly in the lower 80s. If rain coverage
remains low enough, highs on Saturday may reach the middle to upper
80s.

Sunday and Monday...

The persistent upper ridge will attempt to sneak back into the area.
Before it does, some upper impulses may generate isolated convection
on Sunday, but confidence is low.

High temperatures will depend on how far the ridge gets into the
area. Highs near 90 are possible where the ridge rules, with 80s
elsewhere. The most likely locations to see near 90 will be areas in
the southwest forecast area. Guidance continues to waffle though on
the higher temperatures, so confidence remains low to medium.

Tuesday and beyond...

Larger upper troughing developing across the northern part of the
country will bring a cold front into the area Tuesday into Thursday.
The front looks to slow down as it encounters the upper ridge, but
how far south it gets depends on how far north the ridge`s influence
extends.

For now will broadbrush mainly chance PoPs Tuesday afternoon into
Thursday.

Temperatures around 90 may be able to be advected into most areas
ahead of the front on Tuesday, before the front and potential
clouds/rain keep readings in the 80s for Wednesday and Thursday.

&&

.AVIATION (06Z TAF Issuance)...
Issued at 1257 AM EDT Fri Sep 11 2026

Impacts:

- Fog developing at KLAF through daybreak, possibly at KBMG

Discussion:

The front has moved south of the region early this morning with
lower stratus diminishing as well as drier air attempts to advect in
from the north with high pressure. Clouds will linger throughout the
day...especially along and south of Interstate 70 in closer
proximity to an axis of remnant moisture associated with the front.

As the high departs off to the east by late day...deeper moisture
will begin to move back towards the area as an upper low develops
over Missouri. Not out of the question for isolated convection to
develop and move into the southwest half of central Indiana this
evening but confidence far too low to mention in the forecast at
this time. The arrival of the upper low into the area predawn
Saturday will bring a more organized chance for showers closer to
daybreak.

&&

.IND WATCHES/WARNINGS/ADVISORIES...None.

&&

$$

UPDATE...AGM
AVIATION...Ryan
DISCUSSION...50