836
FXUS63 KIND 142240
AFDIND

Area Forecast Discussion
National Weather Service Indianapolis IN
540 PM EST Sun Dec 14 2025

.KEY MESSAGES...

- Cold Weather Advisory in effect through 10 AM Monday across all of
  central IN for potentially dangerous wind chills, particularly
  tonight into Monday morning.

- Freezing Drizzle possible late Tuesday night/early Wednesday.

- Widespread rain likely late Wednesday night into Thursday with
  some minor flooding possible.

- Flash freeze of rain on area roads possible Thursday night.

- Above normal temps and more chances of rain next weekend.

&&

.SHORT TERM (This evening through Monday)...
Issued at 314 PM EST Sun Dec 14 2025

Dry weather conditions are expected in the short term period as an
arctic high moves through the region. Current surface analysis
depicts the strong arctic high centered over the northern MO.
Despite cold air advection the first half of today and a health
snowpack, temperatures have gradually warmed up into the single
digits thanks to plentiful sunshine. Slight additional warming is
possible over the next few hours, but a slight northwest breeze will
keep wind chills near or below zero. A Cold Weather Advisory remains
in effect through 10AM Monday for the potential of dangerous wind
chills, especially tonight into Monday morning.

Expect the arctic high to move overhead this evening into tonight.
Winds are expected to weaken once the pressure gradient relaxes.
Wind speeds will increase slightly late tonight as high pressure
begins to shift east. Light winds combined with clear skies and a
healthy December snowpack should allow for temperatures to quickly
drop. Look for lows to range from the lower single digits across the
far south to sub-zero lower single digits further north. These very
cold temperatures combined with winds increasing slightly late
overnight could result in wind chills as low as -10F to -19F,
especially for northwest portions of central Indiana.

Guidance shows an embedded shortwave within broad troughing moving
across the Great Lakes Region on Monday. While no precipitation is
expected over the forecast area from this system, increasing
southwesterly flow from a tightening MSLP gradient will help to warm
temperatures. Look for highs in the 20s. Shallow diurnal mixing into
a strengthening LLJ aloft should also promote breezy conditions.
Wind gusts around 25-35 mph are possible with the strongest wind
gusts likely focused more over north-central IN. These winds will
make it feel like temperatures are in the single digits or teens
during the afternoon.

&&

.LONG TERM (Monday night through Sunday)...
Issued at 314 PM EST Sun Dec 14 2025

The long awaited pattern change commences Monday night as surface
high pressure that brought Indiana`s coldest temperatures in almost
a year moves towards the East Coast. On the back side of this
surface high southwesterly winds will usher in "warmer" air with
overnight lows only in the 15-20 deg F range. Meanwhile, the upper
ridge that has been a fixture off the CA coast for the last 3 weeks
will gradually build eastward from the Rockies into the Midwest. As
a result, temperatures will continue to climb about 15-20 degrees
between Monday and Tuesday, with highs near or slightly above normal
in the upper 30s to mid 40s. The major limiting factor for greater
warmth Tuesday will be the presence of a broad snowpack. However,
the LWC of the snow is less than normal for December thanks to the
arctic nature of high SLW ratios during Saturdays snow event.

The forecast gets more complicated as we go into Tuesday Night. With
the persistent deep southwesterly low level flow, ow level moisture
will begin to be brought northeast into the region from the Gulf.
Any warmer/moist air over a receding snowpack is a recipe for Dense
Fog, and as such the expectation is for at least patchy conditions to
develop Tuesday night into Wednesday. In addition a glancing blow of
a strong shortwave trough moving north of the Great Lakes and a
weaker shortwave trough moving across the MS valley may be
sufficient to generate light drizzle and/or freezing drizzle (as
both Euro and NAM model soundings indicate near 32F for northern
portions of the FA).

Wednesday`s high temperatures may end up lower than Tuesday`s with
low clouds and/or fog likely to continue for much of the day. Any
drizzle/freezing drizzle is expected to be short lived given the
transitory nature of the shortwave forcing.

A much more pronounced/larger shortwave will move out of the Rockies
into the Plains Wednesday and into the Ohio Valley/Great Lakes
region on Thursday. Strong height falls, ample low level moisture
and a strong cold front spell widespread precipitation Thursday
across the area. NBM pops from 70-90 look very reasonable. Questions
remain on the degree of cooling and any anafrontal forcing that
would support a mix of rain/snow before precip ends Thursday night.
The biggest concern with this system will be both hydrologic and
transportation. The hydrologic concerns are focused on the intensity
and amounts of rainfall /pwats near the 90th percentile for Mid-
December/, cold ground aiding in runoff and potential for some ice
jams. The transportation concerns are focused on the rainfall
washing off salt on area roads, ponding of water and the possible
flash freeze potential Thursday night with lows fall into the low-mid
20s.

Beyond Thursday another warmup commences going into next weekend
with highs expected to approach 5-10 degrees above normal Saturday.
Deterministic models are in good agreement with another shortwave
increasing rain chances across the region Saturday night into
Sunday.

&&

.AVIATION (00Z TAF Issuance)...
Issued at 540 PM EST Sun Dec 14 2025

Impacts:

- Southwest wind gusts peaking at around 20kts Monday afternoon

Discussion:

VFR conditions will continue through Monday evening as strong high
pressure passes over the Ohio Valley. Light and variable winds are
expected tonight with just scattered cirrus. On Monday...return flow
will develop and as the pressure gradient tightens...expect wind
gusts to peak around 20kts in the afternoon from the southwest. Thin
mid and high clouds will pass through the area at times.

&&

.IND WATCHES/WARNINGS/ADVISORIES...
Cold Weather Advisory until 10 AM EST Monday for INZ021-028>031-
035>049-051>057-060>065-067>072.

&&

$$

SHORT TERM...Melo
LONG TERM...Crosbie
AVIATION...Ryan