643
FXUS63 KIND 170641
AFDIND

Area Forecast Discussion
National Weather Service Indianapolis IN
241 AM EDT Mon Aug 17 2026

.KEY MESSAGES...

- One more round of showers and a few storms early today

- Areas of fog tonight with dense fog possible

- Additional thunderstorms likely mid week

- Turning milder and drier late week into next weekend

&&

.DISCUSSION (Today through Sunday)...
Issued at 240 AM EDT Mon Aug 17 2026

The persistent upper level ridge to the south that has kept central
Indiana squarely in the bullseye of ring-of-fire convection for the
last week plus will finally begin to retrograde to the west and
amplify this week.

A cold front to the northwest will push through the area today, with
scattered pre-frontal showers and storms early in the day, primarily
across the southern portions of the area. Rain chances will finally
come to an end late today as the tail end of the boundary exits the
area, with dry weather expected tonight into Tuesday as surface high
pressure pushes into the region.

Light to calm winds, clearing skies, and very moist ground will
likely produce areas of fog tonight despite the decreasing
dewpoints. Dense fog will definitely be on the table given how
incredibly waterlogged most of the area is.

The next chance for thunderstorms will come late Tuesday night into
Wednesday night as one or more shortwave disturbances pivoting
around a large upper low over the eastern Canadian provinces drives
another frontal boundary through the area. Heavy rain and strong to
severe storms will again be a threat, as though instability is a bit
more modest owing to more limited moisture (though still 70th-80th
percentile climatologically), deep layer shear should be fairly
robust. Damaging winds would be the primary threat with this
activity, with at least a modest flash flood threat given the
extreme antecedent conditions.

The more amplified pattern looks to persist late week into early
next, with below normal temperatures and mostly quiet weather
appearing likely, though an occasional upper level disturbance in
the cyclonic flow aloft may necessitate a slight chance of a shower.

&&

.AVIATION (06Z TAF Issuance)...
Issued at 121 AM EDT Mon Aug 17 2026

Impacts:

- Chance for showers and thunderstorms early in the period

- Patchy fog/low clouds possible near daybreak

Discussion:

Scattered showers and a few thunderstorms may impact the southern 3
sites this morning before clearing out as a front pushes into the
area.

This boundary and the plentiful moisture along it may produce patchy
fog and low clouds near daybreak, though uncertainty is high in this
regard given the convection that will be working its way through the
region. If restrictions do develop, all sites should return to VFR
by early afternoon.

Winds will generally be light and variable overnight, becoming more
northwesterly with time as the front passes. A few gusts at IND are
possible in the afternoon.

Winds will again become light and variable to calm after 00Z
tonight, with areas of fog possible as high pressure builds into the
region.

&&

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

&&

$$

AVIATION...Nield
DISCUSSION...Nield