081
FXUS63 KIWX 221906
AFDIWX

Area Forecast Discussion
National Weather Service Northern Indiana
206 PM EST Wed Jan 22 2025

.KEY MESSAGES...

- A period of lake enhanced snow (1-4") late tonight into Thursday
  in sw MI and nw IN. Slippery travel expected at times.

- Mainly dry and milder (near normal) by this weekend and early
  next week.

&&

.DISCUSSION...
Issued at 205 PM EST Wed Jan 22 2025

Chances for light snow is the primary forecast concern tonight
into Thursday as an upper trough and cold front swing through. A
lead, low amplitude, shortwave moving through the southern
Great Lakes as of this writing has failed to produce anything
more than a few light snow showers locally given dry low levels
and weak ascent. This feature exits east late this afternoon
with most locations remaining dry through mid evening. The main
upper trough and cold front look to reach nw IN and sw MI later
this evening into the overnight, and through the rest of the
forecast area Thursday morning/early afternoon. Synoptically
speaking, this system does`t have a lot going for it thanks to a
dearth of moisture and disjointed forcing. This favors holding
with chance PoPs and only light snow accums for most, though a
relatively deep pre-frontal dendritic growth zone (DGZ) could
support accums up to a half inch in spots. The exception will be
closer to the lake where enhancement is expected immediately
along and behind the cold front. 850 mb delta T`s nearing 20C,
inversion heights to 7-8 kft, and the cloud layer clearly within
the DGZ are supportive of lake enhancement in the morning,
transitioning to pure lake effect by Thursday aftn/eve in our nw
flow snow belts. Have snow totals in the 1-2" range in the
South Bend/Elkhart area, with amounts up into the 2-4" range in
Cass/Berrien MI, with the bulk of this likely falling during the
morning and early afternoon thanks to the synoptic support and
seeding. Coverage likely falls off a bit mid afternoon into the
evening hours as incoming dry/subsident air begins to take its
toll on inversion heights. Made no changes to the counties in a
Winter Weather Advisory in Cass/Berrien MI (for blowing snow
into this evening, accumulating snow overnight into Thursday),
but did extend through 00z Friday. A SPS may be needed for the
surrounding counties for slippery travel on Thursday.

A stretch of mainly dry wx and seasonable temps is expected for the
remainder of the period thanks to lower amplitude, quasi-zonal,
flow aloft.

&&

.AVIATION /18Z TAFS THROUGH 18Z THURSDAY/...
Issued at 1247 PM EST Wed Jan 22 2025

VFR conditions should persist across all aerodromes through this
evening, with ceilings expected to lower to MVFR at KSBN after
06z in response to a weak disturbance aloft. A few snow showers
are expected overnight, with more persistent light to moderate
lake effect snows expected post-fropa after 12z. Occasional IFR
conditions are possible at KSBN in heavier bands. MVFR ceilings
will eventually spread into KFWA as well after sunrise on
Thursday. A few stray snow showers could impact the terminal by
mid/late morning into the early afternoon, but confidence is too
low to include mention at this time. Any impacts to KFWA should
be limited and brief in nature.

&&

.IWX WATCHES/WARNINGS/ADVISORIES...
IN...None.
OH...None.
MI...Winter Weather Advisory until 7 PM EST Thursday for MIZ078-177-
     277.
MARINE...Small Craft Advisory until 5 PM EST this afternoon for LMZ043-
     046.

&&

$$

DISCUSSION...Steinwedel
AVIATION...Hammer