955
FXUS63 KAPX 101051
AFDAPX

Area Forecast Discussion
National Weather Service Gaylord MI
551 AM EST Fri Jan 10 2025

.KEY MESSAGES...

- Widespread 1-2" snowfall for most today. Additional lake
  effect snow tonight with localized 2-4" possible.

- Low pressure system returns widespread snowfall across
  Northern Michigan Sunday night through Tuesday. Potential for
  several inches of accumulating snowfall for eastern upper and
  the snowbelts of northern lower continue to increase.

&&

.SHORT TERM /THROUGH TONIGHT/...
Issued at 358 AM EST Fri Jan 10 2025

Pattern Synopsis:

Ridging will continue to slide east of the Great Lakes today as
shortwave troughing rotates down over the region tonight. Said
troughing will be embedded with much more expansive longwave
troughing draped across most of the CONUS east of the Rockies.
Meanwhile, amplified ridging will slide from the Rocky Mountain West
over the Great Plains/Midwest by this evening. At the surface,
forcing provided by the aforementioned shortwave will support a weak
cyclone that will work across the northern Michigan later today into
Saturday morning.

Forecast Details:

Accumulating snow today and tonight -- Snow chances will increase
across northwest lower through the morning as the cyclone continues
to work into the region. Enhanced convergence along/ahead of the
attendant cold front will lead to a focused area of relatively
heavier snow along the Lake Michigan shoreline of northern lower and
extend into western Mackinac county. While a widespread 1-2" is
expected for most areas through daylight hours with this weak
system, this area of enhanced convergence could lead to localized
higher totals between 2-4" by this evening. With lower confidence in
amounts near 4", have withheld issuing any Winter Weather Advisories
during this forecast cycle. Northwest winds behind the front will
usher in lake effect snow across the typical northwest flow belts of
northern lower and eastern upper this evening and tonight. Ample low-
level moisture and over-lake instability will support an additional
2-4" of lake effect snow across localized portions of northwest
lower -- primarily Antrim and Kalkaska counties. Lesser amounts
between T-2" are anticipated elsewhere.

&&

.LONG TERM /SATURDAY THROUGH THURSDAY/...
Issued at 358 AM EST Fri Jan 10 2025

Pattern Synopsis:

Deep mid/upper level longwave troughing over the northern half of
the U.S will keep winter-like temperatures across the Great Lakes
region through the entirety of the long term. Embedded height
disturbances cycling through the base of the trough will keep
conditions active across the northwoods. Light snow showers/flurries
will be over the snowbelts this Saturday, but dissipating as a
shortwave ridge builds subsidence across the CWA. Focus remains on
surface low pressure developing over Alberta and tracking to Lake
Superior Sunday night. Accumulating snow is expected to impact the
majority of the region, with synoptic driven snow this Monday
followed by a pretty strong lake effect response Monday night
through Tuesday.

Midlevel low pressure begins to finally track easterly around the
Wednesday timeframe, giving a break to the region. Northerly flow
will likely continue a lake response, but with rapidly cooling water
temps and no synoptic aid, snowfall will be pretty limited. Midlevel
ridging finally returns subsidence to Northern Michigan at the end
of of the forecast period, giving a bit of a break from this active
January pattern.

Primary Forecast Concerns/Key Messages:

-Low pressure system returns widespread snowfall across Northern
Michigan Sunday night through Tuesday. Potential for several inches
of accumulating snowfall for eastern upper and the snowbelts of
northern lower continue to increase: Latest ensembles have some
relative agreement on the center of low pressure being over lake
Superior Sunday evening. At the same time, midlevel low pressure
from Hudson Bay will advect southward, providing enhancement to the
vorticity maxima. Synoptic driven snowfall totals favor the Upper
Peninsula Sunday night through Monday. The system occludes Monday
evening as Lake effect snowfall begins to spin up across the classic
snowbelt regions on northern lower and eastern upper. Strong low
level westerly (then veering to northwesterly) flow with midlevel
enhancement will likely deliver several inches of snowfall this
Tuesday. Still a bit too early to pinpoint exact accumulations, but
24 hour totals of several inches to numerous counties west of I-75
remains a concern, likely triggering some Winter Weather Advisories
early next week.

&&

.AVIATION /12Z TAFS THROUGH 12Z SATURDAY/...
Issued at 550 AM EST Fri Jan 10 2025

Mainly MVFR CIGs are expected across the northern Michigan TAF sites
through this evening. Drops to IFR CIGs may be possible later this
morning, with the best chances coming at MBL as snow spreads from
west to east across the area. A general 1-2" are in store for much
of the area by this evening, with less than 1" expected near APN.
This snow will bring associated drops in VSBYs to MVFR/IFR at times
across the area through this afternoon. Otherwise, south winds will
turn to northwest winds behind a passing cold front later this
evening and tonight.

&&

.APX WATCHES/WARNINGS/ADVISORIES...
MI...None.
MARINE...Small Craft Advisory until 11 AM EST this morning for LMZ341-
     344>346.

&&

$$

SHORT TERM...DJC
LONG TERM...SJC
AVIATION...DJC