153
FXUS63 KIND 300512
AFDIND

Area Forecast Discussion
National Weather Service Indianapolis IN
1212 AM EST Sun Nov 30 2025

.KEY MESSAGES...

- Winter Storm Warning/Advisory for much of central Indiana

- Snow amounts of 3-7 inches in the Warning area, 1-3 in the Advisory

- Additional snow chances Monday night into early Tuesday, especially
  for south/southeast counties

- Wind chills at night...into the teens through Monday night...and
  then possibly single digits Tuesday night through Thursday night

&&

.FORECAST UPDATE...
Issued at 915 PM EST Sat Nov 29 2025

Surface analysis late this evening shows strong low pressure in
place over western Illinois. A warm front extended SE from the low
across Central IL to SW Indiana. A moderate pressure gradient was in
place allowing for some gusty wind conditions. Radar trends show the
shield of precipitation moving northeast quickly, with more
scattered type snow/rain showers over SW Indiana. Temperatures were
still mainly below 32F. Temperatures near Vincennes had crept to
around 34F.

Snow showers across the area are expected to diminish over the next
few hours as radar trends and the HRRR suggest heavier precipitation
to move quickly to the northeast as the dry sector within this
system arrives across Central Indiana.

Questions remain upon how far north the warm air will arrive and if
any precipitation will remain when it does. HRRR suggests IND temps
reaching 34 by 300 AM, but any significant precip will over at that
point. Thus limited additional mixed precipitation is expected. Some
drizzle will be possible or isolated light snow showers or rain
showers as lower level moisture will remain present, but heaviest
precip should come to and across Central Indiana and additional
accumulations will be minimal.

After a quick surge at or above freezing by 300am, the cold front is
expected to pass and surface temps will quickly fall back below
freezing. Look for lows in the mid to upper 20s as seen at points in
the wake of the front over IA and NRN MO.

&&

.SHORT TERM (This evening through Sunday)...
Issued at 308 PM EST Sat Nov 29 2025

Low pressure over Missouri continues to strengthen. Snow has been
spreading east through the day. However, areas along and south of I-
70 have seen little if any snow as of 3pm. ACARS soundings out of
IND reveal the reason which has been very dry low-level air. This
dry air has been winning the battle against falling snow all day,
though that is expected to change. Radar shows a donut hole shape
indicating snow aloft but none closer to the surface. This radar
donut hole has been shrinking, signifying continued erosion of the
low-level dry layer. A gradual wind shift from southeast to
southwest will also help bring additional moisture northward,
allowing snow to reach the ground more easily. Expect snow to
redevelop within the next 1-3 hours.

Given the late start in snowfall along and south of the I-70
corridor, amounts on the lower end of the forecast spread are now
favored. High-resolution guidance is beginning to trend in this
direction as well with 1 to 3 inches in recent runs. Further north,
near Lafayette, amounts between 5 to 7 inches still look good. We`ve
had a report of 4 inches measured as of 3pm near Kokomo.

Our primary forecast challenge today will be timing the transition
to rain. This depends on the strength of the low and how far into
the occlusion process it gets. These factors will influence the
magnitude of low to mid-level warm air advection ahead of the system
and its surface cold front. All guidance shows warm air advection
fully scouring away residual cold air by 00-04z, with temperatures
warming into the mid 30s. Most if not all of our area will warm to
above freezing during the night tonight. Some high-resolution models
still hold on to near-freezing temps for the duration of the night
across our north, however.

A changeover to rain may substantially cut back on snow totals from
I-70 southward. North of there, it may be too brief or too little
too late to limit expected accumulations. Additionally, a period of
drizzle or light snow flurries appears likely into the day Sunday.
Model soundings are hinting at residual low stratus with sufficient
forcing for at least some light precip. Whether it is drizzle or
light snow will come down to cloud depth and magnitude of forcing.
Some lake-induced snow showers may drift into northeastern portions
of the CWA as well.

Aside from snow, winds look to increase today as the surface low
approaches. Southeasterly winds between 10-20kt gusting to 30kt are
possible at times this afternoon into tonight. There may be a period
of blowing snow before warmer temperatures cause the snow to become
wetter/slushy.

&&

.LONG TERM (Sunday night through Saturday)...
Issued at 308 PM EST Sat Nov 29 2025

Extended Synoptic Overview...Predominately a cyclonic flow aloft,
with a strengthening, negatively tilted upper-level trough across
the Central CONUS early in the week, which will help to reinforce
the slugs of cold air into the Ohio Valley, allowing for continued
below-seasonal temperatures and a progressive active setup that will
feature occasional shortwaves skirting the region.

Sunday Night through Monday... Post frontal snow showers will erode
in the evening hours, perhaps some lingering moisture in some
northern locations. But overall expect quick radiational cooling to
occur with overnight lows falling into the teens to perhaps the
single digits in the northern forecast area. Cloud cover will be the
wildcard, but it appears a minimal concern based off of current
analysis.

Monday night through Tuesday...Confidence continues to increase with
a moderate shortwave that will be associated with or just ahead of a
deep trough axis. The shortwave is progged to congeal south of
central Indiana; however, it does appear a large precipitation
footprint will accompany this next system and could introduce light
snow to central and southern Indiana late Mon into Tue. Guidance has
been consistent with the track, but some ensemble members are
hinting at a northern push which could cause precip chances along
with snow potential to rise.

Wednesday through Thursday...The robust trough axis pivots east
through the region, which will allow for reinforcing shots of strong
cold air advection from the northwest. At this time guidance
indicates a broad surface ridge encompassing much of the region mid-
week behind the frontal passage, but the main storyline for Wed/Thur
will remain with the temps expected to remain well below seasonal
conditions in the 20s.

Friday through Saturday...The progressive pattern will persist as
guidance indicates the surface ridge departing to the east and
allowing a return flow moisture setup, just as yet another deep
500mb trough axis digs into the southern plains. This feature has
been consistent amongst ensemble members. If this all couples
together at the right location, it is possible late in the week into
early weekend another period for snow could be shaping up as the
synoptic pattern could become favorable.

&&

.AVIATION (06Z TAF Issuance)...
Issued at 1212 AM EST Sun Nov 30 2025

Impacts:

- IFR conditions improve to MVFR by 12Z
- A mix of light rain/light snow possible before 12Z
- Flurries possible Sunday morning
- Wind gusts around 30kt into Sunday morning

Discussion:

Some light rain/snow will persist ahead of a cold front that will
move through before 12Z. The cold front will shift winds to
southwest/west and will bring gusts around 30kt.

Low level moisture will be trapped and will keep MVFR ceilings
around during the day Sunday. Cannot rule out brief dips to IFR but
am not confident enough to add that. Winds will diminish later
during the day Sunday.

&&

.IND WATCHES/WARNINGS/ADVISORIES...
Winter Storm Warning until 10 AM EST this morning for INZ021-
028>031-035>041-043>047.

Winter Weather Advisory until 10 AM EST this morning for INZ042-
048-049-051>057-060>065-067.

&&

$$

UPDATE...Puma
SHORT TERM...Eckhoff
LONG TERM...Beach
AVIATION...50