413
FXUS63 KIND 011433
AFDIND

Area Forecast Discussion
National Weather Service Indianapolis IN
933 AM EST Mon Dec 1 2025

.KEY MESSAGES...

- Areas of fog north this morning

- A Winter Weather Advisory for accumulating snow for much of the
  area tonight.

- Wind chills at night into the teens through Tuesday night...snow
  showers Wednesday night before wind chills fall to zero to 15*F

- Light snow to mixed precipitation is possible Friday into Saturday

&&

.FORECAST UPDATE...
Issued at 933 AM EST Mon Dec 1 2025

Some lingering patchy fog remains over north central Indiana where
the greatest snowpack still remains from the weekend snow storm.
This led to very light icing in dense areas with air temperatures
still in the teens. This will end quickly over the next few hours
with a light SE wind aiding in mixing. The snow pack will likely
keep the strong temperature gradient across central Indiana this
morning into the early afternoon, with weak WAA aiding temperature
gains.

The attention then turns to this evening and tonight as a shortwave
pushes through providing widespread snowfall.

&&

.SHORT TERM (Today and tonight)...
Issued at 322 AM EST Mon Dec 1 2025

Bottom Line Up Front...

Snow is expected to move in late this afternoon and continue into
the night before ending from west to east late tonight.
Accumulations of 1 to 3 inches will be common, but some areas may
receive more due to banding. A Winter Weather Advisory will be in
effect for much of the area mainly tonight.

Early This Morning...

Fog has developed across some areas with deeper snow cover across
the northern forecast area, with stratus developing elsewhere. Will
continue to monitor closely for need of any Advisory, but for now
will likely just have a Special Weather Statement for low visibility
and slick spots. Temperatures will be cold.

This morning through mid-afternoon...

Much of the day will be quiet. Fog will lift during the morning.
Stratus and thickening high and mid level clouds will keep skies
mostly cloudy. Temperatures may be able to rise back into the lower
and middle 30s, depending on the thickness of the clouds. Will have
to monitor.

Late afternoon through Tonight...

A northern stream upper trough will bring lift to western portions
of central Indiana late this afternoon, with the northwest forecast
area seeing the best forcing then. There will be some initial dry
air, but at the moment it does not to look to be as strong as the
other day. The atmosphere will be cold enough for all precipitation
to be snow. Will go likely PoPs northwest before 00Z with chance
PoPs across much of the western forecast area by 00Z.

Broad forcing will move into the forecast area tonight from the
northern stream trough, and moisture will be good enough for high
PoPs. Later this evening into the overnight, forcing from the
southern stream will influence the southern and eastern portions of
the forecast area. Will go high PoPs all areas at some point during
the night, and snow will be the precipitation type given the cold
atmosphere.

There will be some features that add uncertainty to snow amounts to
the area. First, frontogenetical forcing will help create banding.
Some models hint and negative EPV above the frontogenesis, which
could intensify the banding. That will have to be watched. These
bands could create relatively large variations in amounts across a
county.

In addition, questions remain on how far north and east the southern
stream forcing will first start impacting the area. This puts
southwestern portions of the forecast area, perhaps even as far
northeast into the Indy area, into potentially lower amounts if the
forcing arrives later and farther east.

Putting all of this together, will go with a Winter Weather Advisory
for all but Sullivan and Knox Counties. Will start the northwest at
22Z and the remainder of the area at 00Z. The snow may start later
in the eastern and southern forecast area, but kept the 00Z start
time there for simplicity. Will go to 12Z Tuesday, but snow will end
before then. Depending on exact timing, the Advisory may be canceled
early if needed tonight.

Amounts of 1 to 3 inches look to be common, with lower amounts in
the southwest. Four inch amounts will be possible in heavier bands.
However, as noted above, amounts may vary a good amount even within
a county due to banding.

Lows will generally be from around 20 to the middle 20s.

&&

.LONG TERM (Tuesday through Sunday)...
Issued at 322 AM EST Mon Dec 1 2025

Cold winter pattern to continue to prevail across central Indiana
into the upcoming weekend as a handful of short wave troughs streak
west to east across central CONUS amid very broad polar trough`s
stagnant occupation of North America.  Dry and cold conditions
Tuesday into Wednesday ahead of snow showers later on Wednesday with
arctic frontal passage...which will bring a frigid Wednesday night
to Thursday night for at least northern zones.  Less confidence for
later in the long term where considerable model divergence surrounds
potential for overrunning precipitation event through late week.

Recent forecast trends are indicating readings not quite so low
south of I-70 where lack of snow pack should allow afternoons into
the mid- to upper 30s most days.  Although counties west of I-69 can
expect a colder night on Wednesday night with readings down to near
10F northwest...highs Thursday across the CWA ranging from 15 to 30F
and frigid Thursday night with single digits across the region`s
northern half and teens over the south.  Wind chills, usually sub-
freezing, are not expected to exceed the mid-20s this week for most
northern zones, and for points south will stay in the 20s both
Tuesday and Thursday.  Overnight wind chills to drop into at least
the teens for all points through Thursday night, with single digit
values across the north Wednesday night and Thursday night.

In terms of comfortability, at least winds will be mainly lighter
than much of the recent late November timeframe, with gusts only
approaching 20 mph Wednesday into Thursday.  The low certainty for
the late week precip chances suggests lower liquid equivalents, with
any hydrometeors most likely starting as light snow Friday and most
likely ending as R-/L- if lingering into the middle of the weekend.
In between these boundaries low chances of mixed precipitation
exist, with the potential for minor travel hazards.  The normal
max/min at Indianapolis through the long term is 44/29.

&&

.AVIATION (12Z TAF Issuance)...
Issued at 608 AM EST Mon Dec 1 2025

Impacts:

- IFR and worse stratus will impact most sites at some point this
  morning, with fog at KLAF
- IFR and worse return after 00Z Tuesday in snow.

Discussion:

Low confidence forecast this morning as stratus meanders about the
area. The stratus will gradually move west, and more is upstream in
Ohio. The ceilings should lift this morning and may mix out back to
VFR. Fog will continue early at KLAF before mixing out.

Later this afternoon, snow will move in from the west and continue
into much of the night. IFR and worse conditions will occur in the
snow.


&&

.IND WATCHES/WARNINGS/ADVISORIES...
Winter Weather Advisory from 5 PM this afternoon to 7 AM EST
Tuesday for INZ021-028>031-035-036-043-044.

Winter Weather Advisory from 7 PM this evening to 7 AM EST
Tuesday for INZ037>042-045>049-051>057-061>065-068>072.

&&

$$

UPDATE...Updike
SHORT TERM...50
LONG TERM...AGM
AVIATION...50