406
FXUS63 KIND 171806
AFDIND

Area Forecast Discussion
National Weather Service Indianapolis IN
206 PM EDT Mon Aug 17 2026

.KEY MESSAGES...

- Clearing skies are expected tonight; Areas of fog, possibly dense,
will be possible.

- Mostly Sunny and less humid on Tuesday.

- Additional thunderstorms likely mid week.

- Turning milder and drier late week into next weekend

&&

.DISCUSSION (This evening through Monday)...
Issued at 206 PM 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 (18Z TAF Issuance)...
Issued at 148 PM EDT Mon Aug 17 2026

Impacts:

- Patchy to areas of fog overnight/early Tuesday morning.

Discussion:

IVF/MVFR ceilings have been a bit slow to improve to VFR this
afternoon, but all terminals should return to VFR no later than 19z.
A narrow line of showers is currently tracking through the
Bloomington area, but this should be clear of BMG by around or
shortly after 18z this afternoon, with precipitation free conditions
expected through the remainder of the period. Northwesterly winds
around 10 to 12 knots have taken hold behind the front. Winds will
become light and variable to calm after 00Z tonight, with areas of
fog possible as high pressure builds into the region, especially
between 8z and 12z Tuesday morning.


&&

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

$$

AVIATION...Williams
DISCUSSION...Puma