661
FXUS63 KMQT 011713
AFDMQT

Area Forecast Discussion
National Weather Service Marquette MI
1213 PM EST Mon Dec 1 2025

.KEY MESSAGES...

- Periods of light to moderate lake effect snowfall is expected
  through the week as a cooler than normal airmass resides over
  the region.

- The next chance of widespread light snowfall comes with a
  fast- hitting Clipper Low Tuesday night into Wednesday.

&&

.DISCUSSION...
Issued at 334 AM EST Mon Dec 1 2025

Satellite imagery and model height analysis showed a large scale
upper level trough over the central and Eastern U.S with an upper
level ridge extending up the West Coast and up through British
Columbia. Shortwave ridging was pushing over the Upper Midwest and a
shortwave trough was over the Central Rockies. Radar and satellite
imagery showed lake effect snow showers over the eastern U.P where
continuing to shift north, offshore as winds turned westerly. There
were also widespread flurries as a stubborn low cloud deck remained
over northwest WI and the U.P. Model guidance was not depicting this
feature very well, the clouds had helped keep temperatures from
falling down into the single digits as guidance suggests, rather
holding in the teens for most locations.

Lingering lake effect snow showers coming into Alger and Luce
counties early this morning will push offshore by mid-morning.
Another band of snow showers will transition northwards across the
Keweenaw as winds become southwest. Accumulations with the LES
should be less than an inch in the east and 1-2" on the western
shore of the Keweenaw. It will be a cold day, with highs in the
upper teens to low 20s, about 10 degrees below average. It will be
mainly cloudy today as mid and upper level clouds increase ahead of
a shortwave ejecting from the Central Rockies with lingering low
clouds as well. The shortwave will reach the eastern Great Lakes by
Tuesday morning. While most of the energy with the system passes
south some light snow is possible for Menominee County and areas
near Lake Michigan tonight. Only a dusting of snowfall is expected.
As far as LES tonight, convergence will increase over the western
lake tonight which should help organize the LES into one or two
narrow bands. While inversion heights and moisture are lacking the
strong convergence should allow for at least moderate snow rates
within this band. There is an brief period that the winds become
more westerly late tonight into early Tuesday which could bring the
heavier snow showers onto the western shore of the Keweenaw with 2-
4" of snowfall possible. Winds will shift southerly Tuesday morning
lifting the LES band back offshore. Elsewhere it will be dry across
the U.P on Tuesday. Highs will be a bit warmer, reaching into the
mid to upper the 20s.

There is pretty decent model agreement in an Alberta Clipper Tuesday
night into Wednesday bringing the next round of widespread snow.
That said, amounts will not be impressive. NBM 24 HR probabilities
of just 2" struggle to reach 20% in the south-central and are only
30-60% over the western spine and north-central. Wednesday night
into Thursday presents 850 mb temps into the -20C to -24C range as a
mid level trough progresses over Ontario, meaning additional LES
showers and cold temps across the UP. Lows Wednesday night will be
in the single digits with highs on Thursday in the teens. Wind
chills will hold in the single digits above/below 0 during this
period. Beyond this midweek system, model guidance diverges on track
and timing of the next clipper system Friday/Saturday, but an active
and cooler pattern looks to continue into December.

&&

.AVIATION /18Z TAFS THROUGH 18Z TUESDAY/...
Issued at 1212 PM EST Mon Dec 1 2025

Given the trend in MVFR cigs holding on longer than anticipated,
keeping things that way through the rest of the daytime today as
winds from the SW continue through the period. However, as IWD has
improved to VFR as of the 17z observation, have them VFR until this
evening. Could see a Bayfield Bomber lake effect snowband move over
CMX tonight; if so, periods of even +SN are possible (low/10% or
less chance). However, most guidance keeps the band north of the
terminal and either in Keweenaw County or Lake Superior.
Nevertheless, could see some drifting at CMX that could reduce vis
down to even IFR at times tonight. Expect clearing late in the
period to bring VFR conditions back over the terminals Tuesday
morning, although lake effect cloud cover may keep cigs MVFR over
CMX Tuesday.

&&

.MARINE...
Issued at 402 PM EST Sun Nov 30 2025

Northwest winds of 20-30 kts with gales to ~35 kts over the east
continue into this evening. Significant wave heights are at their
peak this afternoon between 4-9 ft, highest over the southeastern
waters. Winds settle from west to east to ~20 kts or less by late
tonight, gradually backing west by Monday morning as high pressure
moves in over the Great Lakes. Waves briefly settle around or below
4 ft late tonight/early Monday. Maintained Gale Warnings as is.

High pressure gives way to the east and a low pressure trough
descends southeast over the lake on Monday, increasing southwest
winds to 20-30 kts with a 30% chance for gale force gusts to 35 kts.
Strongest winds will reside over the central waters, particularly
between Isle Royale and the Keweenaw. This increases significant
waves to 4-9 ft again, this time highest waves will be over the
northern waters. Westerly winds fall below 20 kts by Tuesday morning
with waves settling below 4 ft by a similar time.

The pressure gradient tightens with a Clipper Low Tuesday night into
Wednesday. Southwest winds increase once again to 20-30 kts Tuesday
night, veering northwest on Wednesday behind the cold front and
maintaining between 20-30 kts overnight into Thursday. This system
brings the best shot at gales to 35 kts during the forecast period
(40-60% Wednesday into Wednesday night) as a cold airmass descends
overhead accompanied by strong pressure rises. Significant wave
heights build to 6-12 ft, highest southeast. The elevated winds/waves
and cold airmass support light to moderate freezing spray across the
lake, and likely some heavy freezing spray over the north central
waters (60% chance).

Winds fall back down to 20-30 kt for Thursday into Friday with the
resumption of high pressure near the Great Lakes, though uncertainty
increases late this week into the weekend as models differ on the
arrival and strength of the next system.

&&

.MQT WATCHES/WARNINGS/ADVISORIES...
Upper Michigan...
None.
Lake Superior...
None.
Lake Michigan...
None.

&&

$$

DISCUSSION...77/NL
AVIATION...TAP
MARINE...77