151
FXUS63 KIND 141729
AFDIND

Area Forecast Discussion
National Weather Service Indianapolis IN
1229 PM EST Sun Dec 14 2025

.KEY MESSAGES...

- Extreme cold warning in effect for northwest half of central
Indiana from midnight tonight through 11AM Sunday.

- Cold Weather Advisory in effect from midnight through 10AM Monday
  for all of central Indiana.

&&

.FORECAST UPDATE...
Issued at 956 AM EST Sun Dec 14 2025

A bitterly cold airmass has settled across the region with an Arctic
high building in. Current surface depicts the surface high centered
near southwestern Iowa. High pressure will continue to shift east
towards central IN today providing mostly sunny conditions.

Near record temperatures in the single digits below zero this
morning have warmed up slightly since sunrise. These very cold
temperatures combined with breezy conditions at times though is
still producing wind chills as low as -20 to -25F. An Extreme Cold
Warning remains in effect until 11AM across the northwest half of
central Indiana where the coldest wind chills are occurring. A Cold
Weather Weather Advisory is in effect elsewhere through 9AM Monday,
including areas in the Extreme Cold Warning.

Temperatures will warm up slightly into the upper single digits to
possibly mid teens over the far south thanks to plentiful sunshine.
However, wind chills should remain below zero through the day for
most of central Indiana. Look for winds to gradually weaken as the
aforementioned Arctic high builds in.

&&

.SHORT TERM (Today and tonight)...
Issued at 259 AM EST Sun Dec 14 2025

Surface analysis early this morning shows strong arctic high
pressure centered over the plains states. This system was building
east across Illinois and Indiana. GOES19 shows clear skies across
Central Indiana, however some lake cloud was found across northeast
parts of Indiana. GOES19 channel 13 shows the fresh snow band
stretching from South Dakota to Illinois. Temperatures were falling
with many spots in the single digits early this morning. Upstream
over NW IL and IA many areas had below zero temperatures. A moderate
pressure gradient remained across Central Indiana, allowing for
winds of 10 to 15 mph and wind chill values were approaching -20.

Today and Tonight...

Mostly clear and very cold weather is expected through Monday
morning.

Today, models show an upper pattern with strong ridging building
over the high plains and the departed upper trough exiting east and
pushing across the northeastern United States. This pattern will
place Indiana in a favorable location for ongoing subsidence today
and tonight. Forecast soundings and time height sections show a very
dry column with subsidence in play. Meanwhile at the surface, strong
high pressure to the west will be building across Indiana and the
Ohio Valley. thus mostly clear skies are expected today and tonight.

Cold air advection will continue today through at least mid day as
850mb temps are suggested to fall to -20C by mid day. This will
result in continued falling temperatures even after sunrise. Slow
warm air advection will begin this afternoon, allowing highs
temperatures to recover to the single digits. This with winds around
10 mph, will continue to result in very cold wind chill values,
which will start the day around -20 to -25 before improving to zero
to -10 later in the afternoon. Ongoing cold weather advisory will be
on track.

Tonight, warm air advection is continuing, albeit slowly, as we rise
from the depths of the arctic air mass. By 12Z Monday, 850mb temps
are suggested to reach around -4 to -6, as westerly flow begins
aloft. Fresh snow and light winds and clear skies will still allow
for a very cold night with lows in the lower single digits. Winds
will be lighter, resulting in lesser wind chill impacts. Would not
be surprised to see a few traditionally cold spots fall below zero
again.

&&

.LONG TERM (Monday through Saturday)...
Issued at 259 AM EST Sun Dec 14 2025

The long term will start with the lowest temperatures since the
subzero mornings nearly 11 months ago, as the broad arctic surface
high pressure aligned from Arkansas to the Central Appalachians
provides mainly clear skies...and along with the fresh snow cover,
prime conditions for radiational cooling.  Readings will likely
rebound slightly very early Monday from their pre-dawn negative
single digit minimums...as the departing ridge combines with weak
low pressure over the northern Plains to create a moderate gradient
and warm-advective return flow gusting to 10-15 mph by daybreak.

While confidence is increasing in most locations seeing a 25-30
degree diurnal increase Monday with help from gusts up to 15-25 mph
by late morning...this will unfortunately begin as bitter cold
conditions with resultant subzero wind chills through morning hours.
Otherwise, impressive moderation will be the rule into the mid-week,
with Monday night being the only other well below normal period per
lows dipping below 20F.  Moderate, WAA south-southwesterly breezes
are expected Tuesday, as a stronger surface low tracks far enough
north across southern Canada to deter stronger winds from Indiana,
with highs above freezing, if not nearing 40F by late Tuesday.
Finally a seasonably cool day Wednesday as a weak cold fropa brings
a quieter Pacific maritime air mass.

Next precipitation chances will be around the Wednesday night to
Thursday timeframe when a stronger system over the northwestern
CONUS...plunges slightly while crossing the Plains, inducing a
secondary circulation near the western Midwest that, with the help
of tilting H500 energy...should advect and focus Gulf moisture north
into Indiana.  Less certainty in precipitation totals, although with
low 50s dewpoints potentially reaching the CWA, moderate rainfall
amounts are possible, especially for southern zones.

Recent model runs are now suggesting a few colder periods as the mid-
week system departs and the southern appendage of the next arctic
air mass crosses the Midwest with (much more reasonable) below-
normal temperatures around the Thursday night to Friday night
period. Return to seasonable zonal pattern is the most likely
solution for the end of the long term, with low precipitation
chances possible from another weak overrunning set-up.  The normal
max/min at Indianapolis for the long term is 40/26.

&&

.AVIATION (18Z TAF Issuance)...
Issued at 1229 PM EST Sun Dec 14 2025

Impacts:

- VFR conditions this TAF period

Discussion:

Little change from the previous TAF issuance.

Strong, arctic high pressure continues to build across Indiana which
will promote VFR conditions through the period.

Northwest winds today will become light to calm this evening as the
surface high settles over Indiana. Warmer, southerly lower level
flow will arrive on Monday morning.

&&

.IND WATCHES/WARNINGS/ADVISORIES...
Cold Weather Advisory until 9 AM EST Monday for INZ021-028>031-
035>049-051>057-060>065-067>072.

&&

$$

UPDATE...Melo
SHORT TERM...Puma
LONG TERM...AGM
AVIATION...Melo