146
FXUS63 KIND 092236
AFDIND

Area Forecast Discussion
National Weather Service Indianapolis IN
636 PM EDT Thu Oct 9 2025

.KEY MESSAGES...

- Frost Advisory tonight for Central and North Central Indiana

- Dry weather is expected through next week, outside of very
isolated showers Friday night

- Above normal temperatures return next week.

&&

.SHORT TERM (This evening through Friday)...
Issued at 212 PM EDT Thu Oct 9 2025

Main focus in the short term is the frost potential tonight for
Central and North Central Indiana. High pressure remains the
dominant weather influence across the region this week, keeping a
relatively cooler airmass in place. A weakness in the pressure
gradient tonight allows for winds to become very light or calm,
making for great conditions for radiational cooling overnight as
skies will be mainly clear. Dew points today are ranging from the
mid 30s in the north to low 40s across the south, which can be a
good indicator for how low temperatures may fall tonight. Hi-res
guidance does show weak moisture advection across South Central
Indiana this evening and tonight keeping dew points in the 40s,
which should help limit the frost threat in the south. Along and
north of the I-70 corridor outside of urban areas have the best
chance at dropping into the 33-36 degree range by tomorrow morning.
Confidence is high enough in frost tonight along and north of I-70
to warrant a frost advisory from 06z-13z. While the advisory
includes Marion County, thinking the frost threat will mainly be
confined to less urban areas, especially in eastern portions of the
county. The urban heat island should prevent frost around downtown
and highly developed areas. Coldest locations expected to be in the
Wabash River Valley and rural locations in North Central Indiana.

Despite a cold start to the morning Friday, temperatures quickly
rebound into the low 70s as winds become southerly ahead of an
approaching front. An upper low and associated surface reflection
and frontal boundary drop southeast through the Great Lakes tomorrow
and tomorrow night. Warm air advection increases ahead of the front,
but with such a dry airmass in place, not expecting precipitation to
be able to sustain itself as it moves toward Indiana. Expect
increasing clouds Friday afternoon and evening to be the main impact
from this passing system.

&&

.LONG TERM (Friday night through Thursday)...
Issued at 212 PM EDT Thu Oct 9 2025

The next 7 days look very dry once again as high pressure builds on
the northern edge of an Atlantic low this weekend through early next
week. This airmass will have continental origins leading to
abnormally dry surface conditions throughout this period as well.
The one caveat to this pattern will be a very weak thermal low
pushing SE/E late tomorrow through Saturday with an associated
frontal system. Although the air mass will be rather dry, modest
moisture convergence along the front along with a good amount of
lift will likely lead to numerous clouds with a few showers across
northern Indiana.

The diurnal temperature curve will amplify throughout this period
due to the continental air mass` efficient radiative conditions.
This should allow for lows to dip below guidance most night and for
highs to exceed guidance. This should push afternoon temperatures
slightly above climatology this weekend despite weak CAA be hind the
frontal boundary late Saturday and Saturday night. By next week,
height anomalies within midlevel ridging should result in a 5-10
degree temperature increase early next week with highs likely in the
80s once again.

&&

.AVIATION (00Z TAF Issuance)...
Issued at 635 PM EDT Thu Oct 9 2025

Impacts:

- None

Discussion:

Clear skies will continue through the night into Friday morning,
then some VFR clouds will move in from the northwest during the
afternoon. Winds will become light southeast overnight, then become
southwest during Friday with speeds of 10kt or less.

Cannot rule out ground fog near 12Z for all but KIND, but confidence
is not high enough to include at this time.

&&

.IND WATCHES/WARNINGS/ADVISORIES...
Frost Advisory from 2 AM to 9 AM EDT Friday for INZ021-028>031-
035>049-051-052-057.

&&

$$

SHORT TERM...CM
LONG TERM...Updike
AVIATION...50