372
FXUS63 KIND 171847
AFDIND

Area Forecast Discussion
National Weather Service Indianapolis IN
247 PM EDT Sun Aug 17 2025

.KEY MESSAGES...

- Mainly dry through tonight amid seasonable readings and humidity

- Very warm to hot and humid conditions return for Monday-Tuesday
  with overall milder conditions through the rest of the week

- Showers and storms are expected to surround the frontal passage
  Tuesday into Wednesday

&&

.SHORT TERM (This evening through Monday)...
Issued at 245 PM EDT Sun Aug 17 2025

A non-zero chance for isolated convection remains through late
today/early this evening amid dewpoints near 70 degrees and
afternoon heating recovering after a mainly cloudy morning.  Any
showers or lone t-storms are expected to be weak with no impacts.

Overall rain-free conditions are expected to start the work week as
the southern edge of weak Canadian surface ridging glides across the
local region.  The early week will also feature another subtle shift
of this summer`s nearly perpetually humid subtropical ridge...as
heights build near the Four Corners region and drop slightly over
the Great Lakes and at least northern Midwest.  This will be in
conjunction with occasional light northeasterly to easterly breezes
across most zones from the passing northern ridge.  However,
resultant changes in real-feel conditions will be modest, led by mid-
60s dewpoints over northern counties early Monday...and perhaps
isolated morning lows under 65F east of Muncie.

Otherwise, hot and oppressively humid midsummer conditions will
prevail through midday and afternoon hours Monday with the brief and
fleeting northern air quickly returning to low to mid-70s dewpoints
and highs in the upper 80s to low 90s for most locations.  Resultant
afternoon maximum heat indices will range from around 90 degrees for
far northeastern areas to low 100s south/west of a line from
Covington to Spencer to Brownstown.

The short term should be the overall driest tandem of periods since
early last week...courtesy of both lower, more reasonable
precipitable water and generally very weak forcing.  That said,
seasonably copious late day instability along the Illinois border
may couple with near-zero wind shear and very low mid-level lapse
rates to produce a couple isolated ordinary showers/t-storms.

&&

.LONG TERM (Monday night through Sunday)...
Issued at 245 PM EDT Sun Aug 17 2025

Tuesday and Wednesday...

Chances for showers and thunderstorms will persist on Tuesday and
Wednesday as the very warm and humid air mass remains in place
across Central Indiana. Models further suggest north or northwest
flow in place aloft over Indiana with a weak short wave passing on
Tuesday. On Wednesday a weak surface low along with an associated
cool front is shown to be pushing across Central Indiana. Given all
of these features, daily chances, albeit low, will be needed each
day. These systems appear quite unorganized, thus many dry hours
will also be expected.

Highs in the upper 80s to near 90 will be expected on Tuesday, with
slightly cooler temperatures on Wednesday.

Thursday through Sunday...

Strong ridging aloft is expected to be dominate across the American
southwest late this week, extending a ridge axis northeast toward
Indiana. This will result in subsidence late this week and into the
weekend. Mid levels and forecast soundings show dry air in place
during this time. Furthermore, Wednesday`s cold front passage will
allow for surface winds to have a cooler north or northeast
component to them, allowing for cooler temperatures. Look for highs
late this week in the middle 80s.

Of note, small chances for precipitation appear possible on Saturday
and Sunday due to a weak cold front crossing the area. This signal
appears very weak and small at this time, thus confidence is low for
this feature. Will trend toward a dry forecast during this time for
now.

&&

.AVIATION (18Z TAF Issuance)...
Issued at 1207 PM EDT Sun Aug 17 2025

Impacts:

- Mainly VFR Conditions expected.

- IFR conditions possible overnight at HUF/LAF and BMG.

Discussion:

Lingering convection is expected to continue to diminish over the
next few hours, likely leading to dry, VFR conditions earlier than
171800Z. High pressure and subsidence is expected sag southward
across the TAF site this afternoon. HRRR fails to develop any
afternoon convection today as less heating will be felt today due to
the cloudy, rainy morning. Some afternoon and early evening VFR CU
will be possible.

The warm and humid air mass remains in place across Central Indiana.
This in combination with light winds and mostly clear skies expected
will allow dew point depressions to fall to 1-3F overnight. This
will lead to some MVFR to IFR Fog late tonight at HUF/LAF and BMG.

Fog will quickly burn off on Monday morning leading to continued VFR
weather.

&&

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

$$

SHORT TERM...AGM
LONG TERM...Puma
AVIATION...Puma