840
FXUS63 KIND 250035
AFDIND

Area Forecast Discussion
National Weather Service Indianapolis IN
835 PM EDT Sun Aug 24 2025

.KEY MESSAGES...

- A very pleasant final week of climatological summer, with below
  normal temperatures and low humidity

&&

.FORECAST UPDATE...
Issued at 835 PM EDT Sun Aug 24 2025

High pressure continues to dominate the region with prototypical
diurnal trends still expected throughout the evening and tonight.
Slight increases have be made to sky cover forecasts through the
evening due to some lingering mid level cloud cover still remaining.
This should move off to the SE over the next few hours with mostly
clear skies in its wake.

&&

.SHORT TERM (This evening through Monday)...
Issued at 218 PM EDT Sun Aug 24 2025

Surface analysis this afternoon shows high pressure over the Dakotas
with a ridge axis extending SE to MO/IL and Indiana. Cool northwest
surface flow was in place across Central Indiana. GOES16 shows a
large CU field across Central Indiana, resulting partly cloudy skies.
Water Vapor shows strong subsidence in place across Central Indiana
with northwest flow aloft. Dew points had fallen to the lower 50s
due to mixing and subsidence.

Tonight...

Little change is expected in the overall weather as the surface high
pressure to the west and along with continued subsidence will result
in clear skies and light winds overnight. These conditions will also
lead to good radiational cooling conditions and lows in the lower
50s. The last time Indianapolis had a low temperature of 55 or less
was June 10. So tonight will be colder night that we have
experienced in quite some time.

Monday...

Another partly cloudy day will be in store on Monday as NW flow
aloft persists and surface high pressure remains in control of the
weather at the surface. Forecast soundings show afternoon CU
development as convective temperatures are reached. Thus after a
clear morning, skies in the afternoon will become partly cloudy.
Weak cold air advection will remain in place again on Monday as
850mb temps fall to 7C. This will result in highs mainly in the
lower 70s. Overall, ongoing forecast is in good shape.

&&

.LONG TERM (Monday night through Sunday)...
Issued at 218 PM EDT Sun Aug 24 2025

Monday Night through Sunday...

A persistent weather pattern will remain in place across the country
this week. Models suggest strong upper ridging in place over the
western United States, while a deep upper level low pressure system
remains across Quebec and Ontario. This will continue to allow
northwest flow aloft across Central Indiana. Subsidence will also be
in place on the lee side of the ridge, helping to create a large
area of surface high pressure that will allow a continued flow of
cool, Canadian air across Central Indiana.

A few upper short waves will pass within the flow across Indiana,
but these systems will remained moisture starved and will only
amount to a few passing clouds. Otherwise, we should expect a period
of partly cloudy days and mostly clear nights in the week ahead. The
coolest days will be on Tuesday and into Wednesday as the core of
the coolest air arrives with 850mb temps around 5-7C. Warmer
temperatures will arrive for Thursday and Friday as that cooler core
drifts east. Through the week, highs will be mainly in the 70s, with
upper 70s arriving by Thursday and Friday.

&&

.AVIATION (00Z TAF Issuance)...
Issued at 732 PM EDT Sun Aug 24 2025

Impacts:

- None

Discussion:

High pressure continues to build in the upper levels, keeping
stagnant surface conditions over central Indiana. Any remaining
diurnal cloud cover will dissipate through the remainder of the
evening, leaving mostly clear skies across the region. Winds will
slightly back over the next hour as gusts wane, but should remain
consistent overnight from 300-320 at around 5-7kt. There is a chance
for occasional afternoon gusts for the northern 3 sites tomorrow
afternoon, but confidence is not high enough to add for this
issuance.


&&

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

$$

UPDATE...Updike
SHORT TERM...Puma
LONG TERM...Puma
AVIATION...Updike