806
FXUS63 KIWX 011841
AFDIWX

Area Forecast Discussion
National Weather Service Northern Indiana
141 PM EST Mon Dec 1 2025

.KEY MESSAGES...

- Accumulating snow tonight, generally between 2 and 4 inches,
  highest along and south of US 24.

- Additional light snow chances (20-70%) late Wednesday afternoon
  into Wednesday night, mainly near Lake Michigan.

- Sub-zero wind chills expected Thursday night.

&&

.DISCUSSION...
Issued at 141 PM EST Mon Dec 1 2025

Tonight`s synoptic snow event remains on target as a potent
positively tiled upper trough and shot of mainly mid level
moisture/ascent swing east through the Ohio Valley and lower Great
Lakes. The initial corridor of moist isentropic ascent likely
allowing top down saturation for light snow into most of our IN and
MI zones 22-00z, reaching nw OH by 00-01z per latest HRRR/ob trends.
The more pronounced slab of deeper mid level ascent and elevated
fgen on the northern fringes of a 60-70 kt 700 mb jet progress
through this evening into early Tuesday with the bulk of the
accumulating snow. Progressive nature to the wave, and limited low
level moisture return, should keep snow amounts/rates from getting
out of hand despite a relatively deep/saturated DGZ. Did opt to
retain higher SLR`s near 15:1 given this deeper DGZ, which when
combined with a model QPF average in 0.15-0.25" still gives a
general 2-4" type snow total, highest along the US 24 corridor where
localized higher amounts up to 5" appear possible within more
intense mesobanding.

Any LES activity in wake of the system should be uneventful as large
scale subsidence and backing/diminishing winds takes a toll on
inversion heights. A period of weak warm advection then emerges
within increasing southwest flow into Tuesday night and Wednesday
with dry conditions prevailing. This occurs in advance of an arctic
cold front expected to drop through Wednesday night in response to a
piece of the polar low pivoting through the northern Great Lakes.
Some snow may accompany the frontal passage late Wednesday afternoon
into Wednesday night despite the lacking moisture recovery, best
chances near Lake MI where enhancement is expected for a time.
Arctic air funnels in behind the front for Thursday and Thursday
night, with sub-zero wind chills anticipated by Thursday night.

Ensemble guidance overall continues to suggest a northwest flow
regime into this weekend and early next week with below normal temps
persisting. A series of mid level impulses look to be anchored
within an active Pacific jet during this time. This could bring a
few opportunities for snow, though timing and track of these
features at this range is of low confidence.

&&

.AVIATION /18Z TAFS THROUGH 18Z TUESDAY/...
Issued at 1231 PM EST Mon Dec 1 2025

High pressure took over overnight, and this allowed lake effect snow
to come to an end. Meanwhile, another trough enters from the west
and ushers in another chance for snow starting around 00z give or
take an hour or two. VISBY will probably be the most affected by
this storm with the snow and will decrease into IFR/LIFR threshold,
but CIGs will be in MVFR at SBN and LIFR at FWA. Winds will be out
of the east and south ahead of the event, but more like southwest
and west by the time we come to Tuesday morning. Wind intensity is
expected to be rather weak, though.

&&

.IWX WATCHES/WARNINGS/ADVISORIES...
IN...Winter Weather Advisory from 7 PM this evening to 7 AM EST
     Tuesday for INZ005>009-017-018-024>027-032>034-116-216.
     Winter Weather Advisory from 5 PM EST /4 PM CST/ this
     afternoon to 7 AM EST /6 AM CST/ Tuesday for INZ012>015-
     020-022-023-103-104-203-204.
OH...Winter Weather Advisory from 7 PM this evening to 7 AM EST
     Tuesday for OHZ001-002-004-005-015-016-024-025.
MI...None.
MARINE...None.

&&

$$

DISCUSSION...Steinwedel
AVIATION...Roller