153
FXUS63 KMQT 081124
AFDMQT

Area Forecast Discussion
National Weather Service Marquette MI
624 AM EST Sat Nov 8 2025

.KEY MESSAGES...

- Winter Weather Advisories remain in effect beginning tonight
  through Monday for a widespread 2-4 inches of snowfall for all
  except the south-central UP.

- Confidence is increasing in the formation of a strong lake
  effect band impacting the central UP on Sunday, bringing the
  potential for 1-2"/hr snowfall rates. However, confidence on
  the exact placement of this band is low (~20 percent for any
  given area for Marquette/Alger counties).

- 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 414 AM EST Sat Nov 8 2025

KMQT radar returns as of 08Z show only hints of the lake effect
precipitation that brought some good bursts of snowfall to the
central UP yesterday. RAP analysis shows weak surface ridging over
the area, which is responsible for this lull in precip, with flow
aloft primarily being out of the northwest as the UP is on the
southwest periphery of a stacked upper low over James Bay. Upstream,
a compact shortwave is evident (especially in GOES-East WV imagery)
over the Dakotas and eastern Montana. That shortwave will
comfortably miss the UP to the south, though it will back 500mb
winds to the SW ahead of a stout surface trough draped from the
parent low, which will bring significant PVA to the region this
evening. While a few isolated snow showers will come ahead of this
trough, chances of snowfall rates over 1"/6hr are only isolated
pockets of around 30% for mainly Alger County during the day today.

Tonight through Monday, the northerly flow behind the trough will
usher in the coolest airmass of the season, though the NAEFS shows
near-surface temperatures only around the 10th percentile of
climatology, so while it will get cool, it wont be in an
unprecedented way. 850mb temperatures dropping to -14 C over Lake
Superior temperatures which remain warmer than normal at around 9 C
will set up a significantly unstable setup, with NAM BUFKIT
soundings suggesting lake-induced CAPE values of near 1000 J/kg
Sunday. Inversion heights will grow to around 13 kft Sunday with
significant saturation within that inversion and remnant synoptic
cyclonic flow will mean that plenty of ingredients will be present
for significant lake effect snowfall rates depending on where the
bands set up best. There is still a bit of uncertainty in where the
band(s) will be as subtle differences in the wind field generate
vastly different convergent patterns, but there is increased
likelihood of a convergent band setting up and giving 1-2"/hr
snowfall rates over the central UP, per HREF paintball plots. A wide
enough geographical distribution of said bands within the HREF suite
does decrease confidence in any deterministic snow forecast, so
Winter Weather Advisories remain in effect. However, as the forcing
trough moves further into the upper air network this morning, the
hope is that the next HREF run will have an even better handle on
initial conditions and thus give a higher confidence in whether
Marquette, Alger, both, or some other set of counties will need an
upgrade to a Winter Storm Warning. For now, probabilities of a
widespread 2-4 inches for all except the south-central are high
(67%+) with a slight chance (~20%) for any given location from Big
Bay to Munising to get 12 inches by the end of Monday. It will also
be a bit gusty along Lake Superior and the Keweenaw, with gusts of
30-35 mph over 40% likely on Sunday per the 12Z Euro ensemble. This
will add further complications to weekend travel and the Monday
commutes, so if you are on the roads during this event, be prepared
for rapidly changing and potentially hazardous road conditions.
Overnight low temperatures also look to be among the coolest of the
season this far, with the NBM forecast for tonight and tomorrow
night putting temperatures in the teens F in the interior UP. Dry
air intruding with encroaching ridging from the west will put an end
to the heaviest snowfall by the end of Monday, though chances of
lingering snow showers over the east are around 50 percent for
Tuesday.

Uncertainty then grows into the middle portions of next work week as
the longwave troughing continues to gyrate throughout eastern Canada
and the eastern CONUS, and individual embedded shortwaves will
influence the precipitation forecast. A gradual warming trend is
expected especially late in the week as the ridging over the central
CONUS is expected to encroach into the region in some fashion by
next weekend. The CPC gives over 50 percent chances that the
interior west will see above normal temperatures in the 8-14 day
period, with the rest of the UP in the 40-50 percent range.

&&

.AVIATION /12Z TAFS THROUGH 12Z SUNDAY/...
Issued at 623 AM EST Sat Nov 8 2025

MVFR/VFR conditions hold through most of the day until lake effect
snow showers begin to increase ~18-21z resulting in PROB 30s for -
SHSN and MVFR cigs, with those becoming the prevailing conditions
after 00z Sun. Generally light winds <15 kts prevail through the
afternoon before gusty N to NW flow >15 kts returns tonight.

&&

.MARINE...
Issued at 414 AM EST Sat Nov 8 2025

Weak surface high pressure over the Upper Great Lakes will keep
winds below 20 kt through much of the daytime today. However, as a
pair of disturbances transit the region tonight, northerly wind
gusts increase to near 25 kt, with some gusts up to 30 kt over the
west-central lake Sunday. Waves will grow this weekend to around 4-7
ft. As high pressure returns Monday, winds fall below 20 kt Monday
night. The active pattern continues through next work week, with
periodic chances of gales increasing to 30-50 percent with each
disturbance, though the confidence in the placement and timing of
such features is low at this time.

&&

.MQT WATCHES/WARNINGS/ADVISORIES...
Upper Michigan...
  Winter Weather Advisory from 7 PM this evening to 1 PM EST
     Monday for MIZ001-003-004-084.

  Winter Weather Advisory from 7 PM EST /6 PM CST/ this evening
     to 7 AM EST /6 AM CST/ Monday for MIZ002-009.

  Winter Weather Advisory from 7 PM this evening to 7 PM EST
     Monday for MIZ005>007-013-085.

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

&&

$$

DISCUSSION...GS
AVIATION...BW
MARINE...GS