316
FXUS63 KIND 031651
AFDIND

Area Forecast Discussion
National Weather Service Indianapolis IN
1251 PM EDT Thu Sep 3 2026

.KEY MESSAGES...

- Heat Advisory in effect for all of central Indiana through late
  Friday with peak afternoon heat index values up to 108 degrees

- Isolated to scattered thunderstorms will be possible at times
  late today through the weekend.

&&

.FORECAST UPDATE...
Issued at 933 AM EDT Thu Sep 3 2026

Ridging will continue today across central Indiana, but a shortwave
will develop on the periphery and push just to the north and east.
The main forecast problem for today will be if any thunderstorms
that do initiate along this short wave are able to sustain
themselves as they near central Indiana. The current expectation
is for central Indiana to remain dry through the late afternoon
and evening, as steering flow and a mid level dry layer will
inhibit convective progression.

Temperatures and heat index values will be high once again today.
There is some signs of mixing this afternoon which may drop dew
points a few degrees. A few occasional gusts to 18kt will also be
possible as the PBL becomes mixed this afternoon.

&&

.DISCUSSION (Today through Wednesday)...
Issued at 334 AM EDT Thu Sep 3 2026

Mid to upper level ridging continues today, keeping the heat and
humidity in place. Upper troughing to the NE may start to nudge
southwestward into the area late today, weakening the subsidence
aloft. This, plus expected upstream convection, could bring isolated
to scattered showers and storms into the northern part of the
forecast area. However, confidence on how far south the line of
convection gets remains low thus confidence is low on precipitation
for central Indiana. Should these storms reach central Indiana,
can`t rule out isolated severe in the form of brief damaging
winds or hail, but this threat is quite conditional. Timing on the
storms also comes with low confidence and will likely depend on
small scale features. Isolated storms could pop up as early as
this afternoon but most of the latest runs are leaning more so
towards Friday morning convection. Chance of precipitation
continues into Saturday.

Heat will continue into the start of the weekend and a lack of sky
cover and convection will only keep the heat around that much
longer. Highs are expected to remain in the 90s through Friday and
even into Saturday for much of the area with max heat indices near
to above 105.

The ridge axis is still expected to retrograde into the weekend
which could allow for a brief backdoor cold front and temperatures
nearer to normal for the start of the new week with dry weather
likely during this time. Another warming trend looks possible for
the end of the period with a system possibly bringing additional
rain chances for the middle to end of next week.

&&

.AVIATION (18Z TAF Issuance)...
Issued at 1251 PM EDT Thu Sep 3 2026

Impacts:

- Wind gusts around 15-18kt possible this afternoon

Discussion:

VFR conditions are expected through the period. Some cumulus will
pop up this afternoon, with perhaps some passing high clouds at
times.

Isolated convection cannot be ruled out this afternoon, mainly at
KLAF. Will watch the southeast progress of an outflow boundary
across northeast Illinois this afternoon, which might enhance the
chances for convection at KLAF. For now feel odds are too low to
mention.

Additional isolated to scattered convection may be around on Friday
at KLAF/KIND, but again odds are too low to mention.

&&

.IND WATCHES/WARNINGS/ADVISORIES...
Heat Advisory until 8 PM EDT Friday for INZ021-028>031-035>049-
051>057-060>065-067>072.

&&

$$

UPDATE...Updike
AVIATION...50
DISCUSSION...KF