394
FXUS63 KIND 131838
AFDIND

Area Forecast Discussion
National Weather Service Indianapolis IN
238 PM EDT Tue Oct 13 2026

.KEY MESSAGES...

- Multiple rounds of rain and scattered thunderstorms late tonight
  through Thursday night prior to a cold frontal passage

- Sharply colder Friday with northwest wind gusts of 30 to 40 mph.

- Frost and localized freeze potential late Saturday night into
  early Sunday morning

&&

.DISCUSSION (This Evening through Tuesday)...
Issued at 238 PM EDT Tue Oct 13 2026

After another hot afternoon...a frontal boundary will move into the
area from the north tonight and Wednesday with the potential for
rain and scattered thunderstorms. Chances for thunderstorms will
continue through Thursday night prior to a strong cold front passing
through the area. Much cooler air will expand across the region
Friday into the weekend with temperatures recovering to near normal
levels by early next week.

Rest of This Afternoon through Thursday Night

Another very warm and breezy day for central Indiana as most of the
earlier mid level clouds have moved off to the east. 18Z
temperatures were in the 80s with the warmest readings again across
the lower Wabash Valley in the upper 80s. KIND broke their daily
record high shortly after 18Z as well.

Temperatures will climb a few more degrees through late afternoon
with mostly sunny skies and breezy southwest winds continuing. There
remains a strong likelihood of 90 degrees being reached at a number
of locations across the southwest half of the forecast area.

A frontal boundary across the Great Lakes this afternoon will
slowly drift southeast into northern Indiana tonight as it remains
nearly parallel to the mean flow aloft. Progressively deeper
moisture associated with Hurricane Simon currently off the Mexican
Pacific coast will advect northeast into the central Plains and then
pool along the boundary into the region. This will serve as a
catalyst to convective development late tonight as a westerly low
level jet aligns along the boundary across the lower Great Lakes
with additional convection developing initially over Kansas this
evening growing upscale into an expansive convective cluster that
will press into the mid Mississippi Valley by daybreak Wednesday.
The bulk of the storms that develop along the boundary late tonight
will remain to the north of the forecast area until the predawn
hours at the earliest

The convective cluster to our west will track east into the Wabash
Valley Wednesday morning with showers and storms increasing in
coverage into the afternoon as the boundary slides into the forecast
area and rich plume of tropical moisture sidling along it expands
into the region. PWATS will rise to near 2 inches Wednesday
afternoon focused across the southern half of the forecast area with
modest elevated instability supporting a few stronger cells that
will continue into the evening as the boundary settles near or just
north of the Ohio River. Showers may linger in vicinity of the
boundary Wednesday night but high pressure passing to the north
across the Great Lakes will advect drier mid level air into the
forecast area. This will limit rainfall coverage but the presence of
a sharp inversion near 850mb will trap low level moisture and clouds
most if not all of the night.

The front will pull back north Thursday in response to a surface low
ejecting out of the central Plains in tandem with jet phasing aloft.
There remains potential for a few stronger storms...especially ahead
of a strong cold front that will sweep across the area late Thursday
afternoon and evening with damaging winds as the most likely threat.
Behind the frontal passage Thursday night...much cooler air will
advect into the area  1 to 2 inches of rain is possible focused
especially across the northern half of the forecast area by Thursday
evening with winds becoming gusty as well as cold advection
establishes in the post-frontal environment.

Temps...Clouds and periodic showers and storms will keep temps
ranging from the mid 70s north to the lower 80s south on Wednesday
with a muggy airmass. Thursday highs will range from the 70s into
the lower 80s in the lower Wabash Valley ahead of the cold front
before much cooler air arrives for Friday and Saturday. Lows tonight
will largely remain near 70 with low to mid 60s for most of the
region Wednesday night. In the wake of the Thursday night frontal
passage...lows will fall into the low and mid 50s.

Friday Through Tuesday

In the wake of the frontal passage early Friday...the upper trough
will settle and amplify across much of the eastern half of the
country into the first part of the weekend before shifting east by
Sunday. The coolest air of the Fall so far will advect into the area
Friday and Saturday. Intense cold advection combined with a sharp
pressure gradient behind the front will likely bring strong wind
gusts peaking at 35 to 40 mph throughout the day Friday along with
diurnal cu and perhaps a few light showers across the northeast half
of the forecast area. Winds will relax Friday night into Saturday as
a 1035mb surface high moves across the area. Return flow will
develop as early as Sunday with the high moving east into the Mid
Atlantic region. Deep subsidence supports an extended period of
mainly clear skies Saturday into early next week.

Highs in the upper 50s and lower 60s are anticipated on Friday but
the gusty winds and diurnal cu development within the cold advection
regime will likely make that feel a bit cooler. Low level thermals
support the coolest daytime temperatures in the mid and upper 50s
Saturday before recovery back into the low and mid 70s Monday and
Tuesday. While a lack of boundary layer decoupling will likely limit
frost accrual to sheltered locales Friday night...but confidence
remains high in a widespread frost for much of the area on Saturday
night as lows fall into the 30s. Subfreezing temperatures possible
for some of our normal cool spots as well Saturday night. Frost/
Freeze headlines will likely be needed. Lows will return to the mid
and upper 40s by early next week.

&&

.AVIATION (18Z TAF Issuance)...
Issued at 1158 AM EDT Tue Oct 13 2026

Impacts:

- Southwest wind gusts peaking at 20 to 25kts through the afternoon
- Scattered showers developing from the predawn hours into Wednesday

Discussion:

An area of mid level clouds with isolated showers will shift east of
north central Indiana by 18Z with much of the area seeing a decrease
in cloud coverage into the early evening. Southwest winds will gust
up to 20 to 25kts at times through the afternoon before diminishing
during the evening.

Clouds will increase from the northwest overnight as a frontal
boundary drifts into the area from the north. Convection along the
boundary should remain north of the terminals through the first half
of the night with a gradual increase in precipitation coverage
beginning in the predawn hours and continuing into the day
Wednesday. More widespread shower coverage will develop Wednesday
afternoon. Wind direction will be variable on Wednesday withe the
front sliding south into the region.

&&

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

&&

$$

AVIATION...Ryan
DISCUSSION...Ryan