783
FXUS63 KIND 221323
AFDIND

Area Forecast Discussion
National Weather Service Indianapolis IN
823 AM EST Thu Jan 22 2026

.KEY MESSAGES...

- A COLD WEATHER ADVISORY is in effect along and north of a Terre
  Haute to Muncie Line.

- Near zero or subzero lows possible Thursday and Friday nights
  along with potentially dangerous wind chills at or below -10F.

- Winter Storm Watch Sat-Sun with potential for significant
  accumulating snow

- Very cold temperatures persist into next week with potentially
  dangerous wind chills possible at times.

&&

.FORECAST UPDATE...
Issued at 823 AM EST Thu Jan 22 2026

No updates needed to the forecast this morning. High clouds continue
to stream in aloft ahead of a shortwave rotating around the base of
a much larger trough located over southern Canada. Expect high
clouds to gradually increase in coverage and thicken throughout the
day today. This large trough drops south tonight allowing for Arctic
air to advance into the region after about 04z.

&&

.SHORT TERM (Today and tonight)...
Issued at 210 AM EST Thu Jan 22 2026

Surface analysis early this morning showed a weak, dry frontal
boundary stretching from near MIE to BMG and then southwest to
western KY. GOES19 shows a thin area of clouds with this feature.
This weak front was pin-wheeling around much stronger low pressure
in place over eastern Ontario. Very strong, arctic high pressure was
found over the Central and northern plains states. A moderate,
cyclonic, pressure gradient was found across Central Indiana,
allowing for some gusty winds.

Today and Tonight...

A quiet and colder day will be in store. The upper pattern remains
unchanged today and tonight from the past few days, showing broad
cyclonic flow across the northern CONUS east of the Rockies. Again,
Indiana remains in a area favorable for subsidence within this flow
and little to no forcing passes today or tonight.

Within the lower levels strong high pressure over the central Plains
is present and will push east to the Ohio Valley today and tonight.
Forecast soundings today show a dry column, indicative of mostly
sunny skies. Tonight, some upper level saturation is shown to
arrive. This will just result in some passing high clouds.

Regarding temperatures, weak cold air advection is in place today,
but much stronger cold air advection arrives tonight as 850mb temps
plunge to -16C by Friday morning. This will lead to colder
temperatures today with highs only reaching the upper 20s and lower
30.

Temperatures will really plunge tonight when the cold air advection
strengthens, falling into the teens in the evening and to the single
digits overnight. This with a moderate pressure gradient in place
will lead wind chill values around -15F, particularly north of a HUF-
MIE line. Thus a cold weather advisory will be issued for those
areas.

&&

.LONG TERM (Friday through Wednesday)...
Issued at 210 AM EST Thu Jan 22 2026

Friday Through Sunday.

The primary focus of the long term period remains a potent and
highly impactful winter storm system slated to traverse the region
this weekend. Ensemble guidance continues to coalesce around a
solution that brings a deep, moisture-rich plume of Gulf air into
contact with an entrenched, brutally cold Arctic airmass. While the
exact track of the surface low remains subject to minor shifts, the
overall synoptic setup, featuring a strong high pressure center to
the north and a sharpening baroclinic zone favors a significant
winter weather event for much of the Ohio Valley. Confidence is
increasing in a widespread snowfall event, particularly for areas
south of I-70 even as there remains some questions on overall
totals.  Ensemble means suggest the highest probabilities for
greater than 4-6 inches of snow reside across the southern portions
of the forecast area, where the best overlap of frontogenetical
forcing and deep moisture resides.

Where we have higher confidence is in very cold temperatures through
the duration of this event, with highs on Saturday and Sunday
struggling to reach the mid-teens and overnight lows plummeting into
the single digits to potentially below zero. This will create a very
deep DGZ. Because of the sub-freezing depth of the airmass, SLRs are
expected to be well above the climatological 10:1 average. We are
currently forecasting ratios in the 15:1 to 18:1 range, meaning even
modest amounts of liquid equivalent could lead to accumulations and
rapid reductions in visibility.

All that being said, there remains a fairly significant failure mode
for the system as the surface low and associated subtropical jet
will remain well south of even the Tennessee Valley. Winter storms
that far south often overperform on their northern fringe with
models likely overdoing QPF on the northern periphery of the system
where central Indiana lies. The strong Arctic high to our north will
maintain a steady northeasterly wind through the course of the event
advecting cool and dry air into the area with dew points in the
single digits to low teens further complicates the QPF forecast.
Some of the 00Z model guidance has begun to pick up on a more narrow
axis of heavier precipitation, but will need to see this trend
continue before making major adjustments to the forecast. Models are
likely also keeping the precipitation window for too long with GFS
and Euro showing snowfall over much of a 36 hour window when the
true window is likely to be lower.

After collaboration with neighbors, we have gone ahead and issued a
Winter Storm Watch for the I-70 corridor and points to the south
where confidence is highest in at least 3+ inches of snow with the
thought that the northern portion of the Watch may end up in an
Advisory while the far south ends up in a Warning. This gives us the
flexibility to continue to monitor forecast trends and adjust
accordingly.

Monday and Wednesday.

The pattern looks to remain active but cold heading through the
middle of next week, as a trough persists over the Eastern US
following the departure of the weekend system. This setup will
maintain northwest flow across central Indiana, keeping highs in the
20s and lows in the single digits or teens through Tuesday with
lower chances for sub-zero temperatures.

&&

.AVIATION (12Z TAF Issuance)...
Issued at 534 AM EST Thu Jan 22 2026

Impacts:

- A few wind gusts to 22kts through 14Z

Discussion:

VFR conditions expected through the TAF period with clouds generally
remaining at or above 10kft. Westerly winds may continue to gust to
around 22kts through 14Z, especially at LAF but expect winds more
in the 8-12kt range through much of the rest of the TAF period. Dry
and quiet weather continues into tonight with winds slowly becoming
more northwesterly.


&&

.IND WATCHES/WARNINGS/ADVISORIES...
Cold Weather Advisory from 1 AM to 1 PM EST Friday for INZ021-
028>031-035>049-051-052.

Winter Storm Watch from Saturday morning through Sunday evening
for INZ042-045>049-051>057-060>065-067>072.

&&

$$

UPDATE...Eckhoff
SHORT TERM...Puma
LONG TERM...White
AVIATION...White