738
FXUS63 KIND 201634
AFDIND

Area Forecast Discussion
National Weather Service Indianapolis IN
1234 PM EDT Thu Aug 20 2026

.KEY MESSAGES...

- A few showers are possible over southeast Indiana into this
  afternoon

- Generally drier late this week through early next week, but there
  is a chance for showers and storms late Friday into Saturday

&&

.FORECAST UPDATE...
Issued at 938 AM EDT Thu Aug 20 2026

Rain has diminished and moved off to the southeast of the forecast
area this morning. Lower clouds linger in the wake of the rain but
skies are clearing from the northwest. 13Z temperatures ranged from
the mid 60s to lower 70s.

Only  minor updates needed for the rest of the day as a cold front
drops south away from the region. A trailing upper level wave might
be just enough to generate a few showers in our southeast counties
this afternoon but most of the area will enjoy dry weather all day.
Lingering moisture will keep lower clouds around through the morning
gradually mixing into a cu field through the afternoon. As drier
air advects in from the north...expect a gradual clearing trend
from north to south into this evening.

Low level thermals support highs in the upper 70s and lower 80s.
Zone and grid updates out.

&&

.DISCUSSION (Today through Wednesday)...
Issued at 315 AM EDT Thu Aug 20 2026

Early This Morning...

Following a surprisingly potent quasi-linear convective system that
twisted from the western I-70 corridor down to the I-69 corridor
immediately south of Indianapolis through the wee hours...a few non-
severe cells amid overall scattered convection, will continue to
track to the east-southeast into pre-dawn hours.  Localized flash
flooding will continue to be the greatest threat...as is the case in
the Putnam County to northwestern Morgan County area from the recent
cell whose head sat and spun over these counties while producing
heavy rainfall rates.  Locally dense fog will be another concern
towards daybreak...with deteriorating visibility trending from NW to
SE.  Most of the storms and heavier showers should be south of the
area by 12Z (8 AM EDT).

Today...

Will keep some low PoPs going early today in the far south to
account for any lingering rain.

Otherwise, outflows from previous convection will be south of the
area today, but the cold front might still ignite isolated showers
or storms this afternoon in the far south part of central Indiana.
Better shear should be south of the area, so severe storms are not
expected.

Most of the drier air won`t arrive until tonight, so it will still
feel humid. Highs will be in from around 80 to the lower 80s.

Tonight and Friday...

Surface high pressure will build in and provide quiet weather during
this period. Slightly drier air will briefly move in tonight, but
upper 60s dewpoints could return by Friday afternoon. Lows will be
in the lower to middle 60s tonight with highs in the lower to middle
80s on Friday.

Friday night into Saturday...

An upper wave will help push a cold front through the area during
this time. Current expected timing has storms moving in Friday night
and likely weakening as they move in. Storms then redevelop
Saturday afternoon, mainly east as the front moves through and
exits. Of course will have to monitor in case timing of the system
changes. Depending on the timing of the front and rain, highs on
Saturday may only be in the upper 70s north to middle 80s south.

Saturday night through Tuesday night...

Surface high pressure will likely dominate during this period,
providing dry weather. Northwest flow will keep hot air well west of
the area, and central Indiana will see near to below normal
temperatures. Lows in the 50s will become widespread by Sunday
night, with highs generally in the mid 70s to lower 80s.

Wednesday onward...

Another upper wave/surface cold front will move through around
Wednesday. Best moisture will be kept south of the area, so for now
will only have some low PoPs. Seasonable temperatures are expected.

&&

.AVIATION (18Z TAF Issuance)...
Issued at 1235 PM EDT Thu Aug 20 2026

Impacts:

- MVFR ceilings remain possible through the afternoon but clouds
  scattering
- Chance of fog at outlying terminals late tonight and early Friday

Discussion:

Drier air continues to filter into the region from the north slowly
but MVFR stratocu has been stubborn to mix out to this point with
moisture lingering in the boundary layer. Expect stratocu to further
mix out into a VFR cu field through the afternoon with light
northerly winds. Mainly clear skies initially tonight with near calm
winds over the saturated soils will support fog development late
tonight into Friday morning...especially at the outlying terminals.
MVFR ceilings may also briefly impact the sites. Expect clouds to
mix out to a cu field quickly on Friday with variable winds at 5kts
or less.

&&

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

&&

$$

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