105
FXUS63 KMQT 092344
AFDMQT

Area Forecast Discussion
National Weather Service Marquette MI
644 PM EST Sun Nov 9 2025

.KEY MESSAGES...

- Another round of moderate to heavy lake effect snow is
  expected late tonight into Monday. Snowfall rates between
  0.5-1"/hour Monday morning rapidly drop visibilities and
  accumulate on roadways, creating hazardous travel during the
  morning commute.

- Winter Weather Advisories remain in effect through Monday for
  additional accumulations of 1-4 inches with difficult travel
  conditions possible during the Monday morning commute. Winter
  Storm Warnings for Marquette and Alger counties also hold
  through Monday for an additional 3-6 inches of snow.

- While snowfall rates fall off significantly late Monday into
  Tuesday, active weather pattern continues through the work
  week with a slight warmup expected to bring periodic rain and
  snow showers to the forecast.

&&

.DISCUSSION...
Issued at 408 PM EST Sun Nov 9 2025

Afternoon GOES water vapor imagery and RAP analysis shows the
elongated mid trough/closed low extending from far eastern Hudson Bay
across Northern Ontario, with the southern portion of the wave
digging across the Upper Great Lakes. A mid level ridge is building
upstream well to the west with a high pressure noted over the
Plains. The radar mosaic is lit up with numerous snow showers over
the west half as a result of the PVA and strong thermodynamics
present. Mesoscale Analysis plots 850 mb temps between -13C to -14C
across Lake Superior, which currently is a few degrees C warmer than
normal at 9C, yielding strong delta-Ts and lake induced instability
of a few hundred J/kg. With deep moisture still present and
inversion heights up to ~10kft, additional accumulations this
afternoon and evening over the west half are forecast between trace
to 3". Higher amounts to 3-6" during that period are expected in the
north-central where low level convergence and upslope flow boost
snowfall totals. Heavier snowfall rates around 1"/hr in that area
may also result in difficult travel at times yet today.

Late tonight through Monday morning, the second round of moderate to
heavy LES showers kicks in with a southward dropping surface trough
and elevated cold front. Although inversion heights begin their
descent during this period to between 5-7kft, delta-Ts remain intact
and low level moisture will support widespread light accumulations
of T-3" over the northwest to north wind lake effect snow belts.
Higher amounts between 3-6" are expected over the north-central UP
with localized amounts up to 8" near the Marquette/Alger county line
where low level convergence boosts totals. This is where the 11/9
12Z HREF shows probabilities of snowfall rates exceeding 1"/HR
between 30-60% with 60-90% chances for at least 0.5"/HR rates ahead
of the monday morning commute into the early afternoon hours. Opted
to hold onto the Winter Weather advisories for possible impacts and
light accumulations into the morning commute. Winter Storm Warnings
remain in effect for Marquette/Alger counties through Monday as
heavy snowfall rates rapidly drop visibilities and accumulate on
roadways, creating hazardous travel during the morning commute.

A high pressure descending from the Plains into the Lower
Mississippi Valley continues to extend ridging overhead through
Monday evening, drying out the airmass. At the same time, a brief
positively tilted mid level ridge is moving in and 850 mb temps are
warming, decreasing the delta-Ts. This gradually dwindles LES off
from west to east on Monday. North to northwest winds will be a bit
gusty near Lake Superior, particularly in the Keweenaw where 20-30
mph gusts are forecast. Otherwise, temps will feel warmer as highs
rise back up in to the 30s for most.

Clouds increase again for Monday night, but one last colder night in
the mid teens to upper 20s is expected. Any lingering LES over the
east will be low impact as accumulations will be limited to a
few tenths.

The midweek pattern resembles northwest flow aloft with a ridge
building over the western CONUS through Wednesday, then tracking
toward the Great Lakes toward next weekend. A pair of shortwaves
approach the Upper Great Lakes through this northwest flow Monday
night into Tuesday, sending a low pressure system across northern
Ontario Tuesday through Wednesday morning. There remains quite a bit
of spread in this track as the wave currently resides offshore yet
over the Pacific, but sampling should improve within the next 12-24
HR. The southern shortwave tracks south of the UP on Tuesday and
model soundings indicate drier low levels limiting precip regardless
until late moring over the west on Tuesday with higher chances (20-
40%) over the east in the afternoon when precip with the low
pressure catches up. All the while, 850 mb temps will be cold enough
for lake effect. With the warming pattern, not all precip will fall
as snow as temps begin to rise well above freezing during the mid
week.

What has more forecast confidence is the breezy west-northwest winds
expected on Wednesday. Pressure rises and a weak resurgence of
colder air will support gusty winds in the wake of the low pressure
system`s frontal boundary with frequent gusts between 20-30 mph.
Gusts in the Keweenaw and near the Lake Superior shores will push
into the 30-40 mph range; NBM probabilities of gusts exceeding 40
mph in the Keweenaw are between 30-50%.

Eventually the mid level ridge makes it to the Great Lakes by
Friday, continuing the warming pattern and further diminishing the
lake effect PoPs. Highs returning to the 40s, maybe even low 50s
with lows in the mid 20s to 30s are expected next weekend. This
brief reprieve from precip does not appear to hold on fro long as a
deep rough emanating from the Rockies late next week sends a low
pressure through the region. Spread is fairly high for exact details
in timing/track, precip likely will fall as rain given the continued
warming pattern.

&&

.AVIATION /00Z TAFS THROUGH 00Z TUESDAY/...
Issued at 644 PM EST Sun Nov 9 2025

Mainly VFR conditions at the terminals this evening as radar shows
the primary lake effect snow band over the central U.P. shifting
westward into Baraga County, with another band bringing variable
MVFR cigs to KIWD. Expect snow showers to pick up intensity again
overnight, with conditions trending back to MVFR/IFR 06-10z. Expect
heaviest snow roughly 10-15z Mon morning, with periods of LIFR at
KIWD and KSAW. Showers finally taper off late in the day as
conditions improve to VFR after 21z Mon.

&&

.MARINE...
Issued at 408 PM EST Sun Nov 9 2025

Northerly winds will increase this evening to 15-25 kts across the
lake, strongest over the western third where a low chance (~15%) of
gusts up to 30 kts resides. Winds become more uniformly north-
northwest by Monday morning, this time increasing over the central
third of the lake between 20-30 kts with a 15-25% chance of gales to
35 kts. This increases wave heights to 4-8 ft over the central two
thirds of the lake on Monday. As ridging settles southeast Monday
night, winds drop below 20 kts and waves fall below 4 ft Monday
evening, then winds shift southwest by Tuesday ahead of the next
system.

A low pressure tracking to the north of Lake Superior Tuesday
through Tuesday night supports a active midweek on the lake.
Southwest winds between 15-25 kts, gusts up to 30 kts over the west
are likely before the low`s passage into Tuesday morning. This will
be followed by widespread 20-30 kt westerly winds Tuesday night
through Thursday as strong pressure rises are accompanied by a
colder airmass crossing over the lake. There is decent confidence
for gales to 35-40 kts Wednesday into Thursday (50-70% chance), but
exact timing will depend on the track of the low and its frontal
passage. A Gale Watch is increasingly likely in future forecast
package updates.

&&

.MQT WATCHES/WARNINGS/ADVISORIES...
Upper Michigan...
  Winter Weather Advisory until 1 PM EST Monday for MIZ001-003-
     004-084.

  Winter Weather Advisory until 7 AM EST /6 AM CST/ Monday for
     MIZ002-009.

  Winter Storm Warning until 7 PM EST Monday for MIZ005-006.

  Winter Weather Advisory until 7 PM EST Monday for MIZ007-013-
     085.

Lake Superior...
None.
Lake Michigan...
None.

&&

$$

DISCUSSION...77
AVIATION...CB
MARINE...77