318
FXUS63 KIWX 101120
AFDIWX

Area Forecast Discussion
National Weather Service Northern Indiana
620 AM EST Wed Dec 10 2025

.KEY MESSAGES...

- Colder air returns later today and rain will end as some brief
  light snow. 1-2" of lake effect snow is possible this evening
  and overnight.

- 1-3" of snow is then expected mainly south of US-30 on
  Thursday night.

- More light snow is expected this weekend, along with very cold
  air. Wind chill values may drop below -10F Sunday morning.

&&

.DISCUSSION...
Issued at 312 AM EST Wed Dec 10 2025

Our CWA is now firmly in the warm sector of 990mb surface low
crossing southern Lake MI. Several peak gusts around 35 kts over the
last few hours as we almost mix into 50+ kt LLJ just above 900mb.
Strong stable layer will prevent tapping into higher gusts though
and by the time mixing increases with cool/dry air advection later
today, the gradient will be much weaker. Expect a few 35 kt gusts to
continue at times through the morning but should remain safely below
advisory criteria. Almost entire CWA now reporting rain as well with
just Hillsdale reporting 34F and -SN/UP. Warm air will continue
advecting north and bulk of precip through the morning will remain
liquid. Of course, colder air does return by the afternoon as
surface low exits and northwesterly flow returns. Precip will likely
end as some light snow especially in our northern zones but
little/no accumulation expected given commensurate arrival of dry
air and loss of forced ascent. Any accumulating snow will be tied to
a brief window of marginally favorable conditions for LES this
evening and overnight. NNW flow pushes 850mb temps to around -13C
tonight but inversion heights are a paltry 5 kft and 0-2km theta-e
lapse rates remain positive. A brief window of weak low level
convergence around 21Z this afternoon will probably be the best
chance for a slightly more organized band. Winds slowly back
overnight though further limiting the lake response. Overall an
isolated 1-2" in our NW zones is all that is anticipated through Thu
AM. Overnight lows do drop back into the teens. Winds relax tonight
but remain steady near 10 mph yielding Thu AM wind chills in the
single digits.

Next clipper system arrives Thu night with the next round of light
snow. CVA forcing is much weaker with this system. Expect a classic
clipper setup with just a brief and narrow region of WAA/fgen
sliding through the region Thu night. Expect a fairly tight gradient
in QPF/snowfall given such narrow, modest forcing in an otherwise
dry/stable environment. Several of the newest 00Z deterministic runs
even suggest areas along/north of US-30 will remain entirely dry.
Still some uncertainty in exact track based on ensemble guidance
though, so maintained some lower PoP`s/QPF further north but do
expect the highest totals (likely 1-3") to remain south of US-30.

Still expecting another clipper this weekend with very cold air.
Details on snow amounts, particularly the lake effect component, are
difficult to pinpoint this far out but do expect temps around zero
and wind chills of -10 to -20F, especially Sunday morning. Luckily
this cold/snowy pattern looks to finally break by next week.

&&

.AVIATION /12Z TAFS THROUGH 12Z THURSDAY/...
Issued at 620 AM EST Wed Dec 10 2025

Low pressure center is currently passing north of the area and
rain will slowly taper off during the next few hours. As winds
switch around to northwest, colder air returns and a brief
period of snow with IFR stratus is possible before synoptic
precip ends this afternoon. Lake effect snow will then be
possible during the late afternoon and evening. Lake effect
parameters are not highly favorable and there is some
uncertainty in where exactly the bands set up. Brief IFR may be
possible but will hold MVFR for now.

&&

.IWX WATCHES/WARNINGS/ADVISORIES...
IN...None.
OH...None.
MI...None.
MARINE...Gale Warning until 7 PM EST this evening for LMZ043-046.

&&

$$

DISCUSSION...AGD
AVIATION...AGD