860
FXUS63 KIND 151034
AFDIND

Area Forecast Discussion
National Weather Service Indianapolis IN
534 AM EST Mon Dec 15 2025

.KEY MESSAGES...

- Cold Weather Advisory in effect through 10 AM across all of
central IN for potentially dangerous wind chills.

- A warming trend begins today.

- Widespread showers likely Thursday, minor flooding possible...
  followed by temperatures plummeting 30-40 degrees into Friday

&&

.SHORT TERM (Today and tonight)...
Issued at 322 AM EST Mon Dec 15 2025

Surface analysis early this morning shows strong, arctic high
pressure in place over the Ohio Valley. This large high was
dominating the weather from Ontario and Quebec, across Indiana to
Texas and the deep south. Aloft, strong ridging was found over the
western CONUS, while the weekend system upper trough was now found
exiting New England. This was resulting in a quick, fast and cold NW
flow aloft, streaming from the northern plains to Indiana. Some high
cirrus was found within that flow passing across Central Indiana
from time to time. Temperatures were very cold. Many locations were
below zero, however, lighter winds tonight were only resulting in
wind chill values of -10 to -19.

Today and Tonight...

Quiet but warmer weather is the main weather story for today and
tonight as the arctic air mass slowly moves east. Models suggest
little overall change in the upper pattern today and tonight as
quick and fast northwest flow is expected to persist. Little in the
way of any forcing in the pattern is expected, and no
precipitation will occur.

Within the lower levels, strong warm air advection is in play at
850mb as the arctic air drifts eastward, where temperatures rise to
near -2C by 00Z Tuesday and 4C by 12Z Tuesday. This will result in
weak lift within the column today and tonight, but this will not be
enough to cause any precipitation. Forecast soundings today and
tonight remain unsaturated through the column and overall show a
slow warming trend. Some high saturation is noted from time to time
due to some passing CI that is expected. Thus a mostly sunny day and
a mostly clear night are expected once again.

Given our strong warm air advection today. Highs will recover to the
middle and upper 20s this afternoon. The ongoing cold advisory
through the morning hours appears on track with single digits or
less expected through mid morning. No changes to this ongoing
headline.

With ongoing warm air advection tonight, lows will be much warmer,
falling only to the teens.

&&

.LONG TERM (Tuesday through Sunday)...
Issued at 322 AM EST Mon Dec 15 2025

The synoptic pattern through the long term will be generally zonal
and seasonably cool...with occasional stronger troughs/storm systems
bringing unsettled and-or briefly sub-freezing conditions.  Warm-
advective southerly breezes will continue the short term`s
moderation into Tuesday and Wednesday, with readings most often in
the 30s Tuesday night-Wednesday night.  Another strong early winter
storm crossing the Upper Midwest into the northern Great Lakes by
Thursday will bring a stronger gradient...with robust to gusty
southerly flow advecting ample Gulf moisture into the region. Expect
at least 6-12 hours of rain showers within the Thursday calendar day
...with the potential for widespread moderate rainfall should the
northern storm occlude/slow as expected.

Expect the 50F mark to reach several central Indiana counties
Thursday ahead of a potent cold front that should bring low
temperatures by early Friday 15-20 degrees below normal, and perhaps
wind chills values down into the single digits.  Blustery yet dry
conditions to end the workweek...as subsequent narrow upper trough
should allow heights to begin rising before the weekend begins. More
warm advective flow from surface high pressure to our southeast for
the weekend.  Following system to be weaker and farther south, and
with a quicker return of Gulf moisture...should allow for low
chances of drizzle/rain showers as the long term ends, with low
confidence in any opportunities for light frozen precipitation as
the disturbance departs.

&&

.AVIATION (12Z TAF Issuance)...
Issued at 534 AM EST Mon Dec 15 2025

Impacts:

- VFR Conditions this TAF period.

Discussion:

Little overall change to the ongoing forecast since the last
issuance.

VFR conditions will continue through this TAF period as as strong
high pressure begins to exit the Ohio Valley. Southerly winds are
expected today with some high, scattered cirrus passing within the
flow aloft.

Forecast soundings through the period continue to reveal a dry
column, with slow warm air advection in play.

Thin mid and high clouds will pass through the area at times as the
flow aloft becomes more zonal.

&&

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

&&

$$

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