087
FXUS63 KMQT 121144
AFDMQT

Area Forecast Discussion
National Weather Service Marquette MI
644 AM EST Wed Nov 12 2025

.KEY MESSAGES...

- Warmer temperatures will result in daytime snow melt, which
  may refreeze overnight. This may result in ice or black ice
  and isolated hazardous roadways during the morning commutes
  today and Thursday morning.

- Northwest winds near 40 mph are possible near Lake Superior
  and in the Keweenaw Wednesday (~50% chance).

- A Gale Warning is in effect for much of Lake Superior late
  tonight through Wednesday for northwest 34-40 knot winds.

- Lake effect rain and snow showers are expected into Thursday
  with little to no impacts.

- A gradual warm up to above normal temperatures is expected by
  this weekend.

&&

.DISCUSSION...
Issued at 155 AM EST Wed Nov 12 2025

Shortwave has been noted diving southeast along the northeastern
lakeshores of Lake Superior on GOES Water Vapor imagery atop a
surface trough/cold front that`s extending south across Upper
Michigan. Synoptic precip was largely limited mainly to Ontario or
Lake Superior in Canadian waters from east of Keweenaw Point to near
the Soo. Behind the front, lake effect showers have been noted on
KMQT radar pressing into Alger and Luce counties and west of
Marquette in the Michigamme Highlands. Webcams also show precip
across the higher terrain of the Keweenaw and Gogebic Range. Some
snow appears to be mixing into the lake effect rain showers, but
accumulations haven`t amounted to much given the mild surface and
road temperatures being observed across the region. As the night
progresses we could cool into the low 30s to upper 20s. Given the
cloud cover though and temperature trends so far, this may be
difficult to come by. Should this occur, yesterday`s snow melt could
refreeze on roadways, resulting in black ice for this morning`s
commute.

Across CONUS, mid-upper level ridging is observed stretching north
across the western third with troughing across the eastern third.
This places our forecast area in northwest flow aloft and at the
mercy of any weak or low amplitude shortwaves caught in the flow.
The first is the current shortwave migrating through the Upper Great
Lakes. The second and weaker impulse comes late tonight into early
Thursday morning with a similar track. With 850mb temps expected
generally near -6C in this period, lake effect showers are expected
to persist downwind of Lake Superior until surface ridging builds
into the region from west to east tonight and Thursday. Shower
activity will be confined mainly in the traditional northwest wind
snowbelts today but will diminish across the west given an increased
dry near surface layer and influence on the building ridge.
Scattered shower activity should continue in the east through at
least Thursday morning or early afternoon. Ptype during daytime
hours will be rain or a mix of rain/snow but cooler temps overnight
should allow snow showers to be more common. The lack of significant
moisture though will make accumulations and impacts hard to come by.

With the punch of cold air advection bringing 850mb temps to near -
6C occuring this morning and coinciding with pressure rises and
daytime mixing, breezy northwest winds should be expected today. 20-
30 mph gusts will be widespread, with gusts approaching 40 mph being
common in the Keweenaw and near Lake Superior. Recent EC ensemble
mean winds are pinged above 40kts by this afternoon, but model
soundings and raw output from all other guidance packages aren`t as
aggressive. NBM probabilities for >40mph winds also only peak near
50%. Given this lack of consistency, opted not to issue a Wind
Advisory, but will be worth monitoring through the day.

Ridging will keep the region dry Friday as a deepening low pressure
migrates through northern Manitoba. The past 24 hours has provided a
slightly better sense of when this system`s cold front will swing
through the region; between the EC/Canada/GFS deterministic
packages, the front moves west to east through the region Saturday,
with precip potential being maximized across the east half by
afternoon given left exit region dynamics from an amplifying
jetstreak at 300mb to the south. Strong cold air advection,
potentially on the order of 20C in 24 hours, will make for breezy
northwest winds Saturday night and Sunday while lake effect rain and
snow showers press downwind into the traditional northwest wind
snowbelt regions. High pressure will slowly build into the Great
Lakes afterwards, but there`s differing opinions on when it will be
enough to end the lake effect. At this point, guidance suggests
shower activity could linger into Monday or Tuesday.

The warming trend continues into this weekend. Expect each day
Thursday through Saturday to be just a little warmer then the day
prior, with highs peaking Saturday in the upper 40s to 50s.
Overnight temperatures fall to or below freezing tonight and
Thursday night, which may result in isolated pockets of hazardous
driving for their follow on morning commutes due to black ice
formation. Friday night, temperatures may remain above freezing for
most of the forecast area (40-80% Friday night east to west per
latest NBM run).

&&

.AVIATION /12Z TAFS THROUGH 12Z THURSDAY/...
Issued at 644 AM EST Wed Nov 12 2025

VFR conditions prevail at all TAF sites this morning, though models
suggest about a 60 percent chance of brief periods of MVFR ceilings
at SAW and CMX this morning. The most impactful weather within this
TAF period will be the gusty west to northwest winds, as CMX is
already gusting to 35 kt. IWD and SAW will see gusts to 20-25 kt
today. At all sites, winds will relax somewhat tonight at around 5-
10 kt, backing somewhat to be more directly out of the west to
southwest.

&&

.MARINE...
Issued at 155 AM EST Wed Nov 12 2025

Westerly and northwesterly flow have been observed on Lake Superior
behind a front trough that moved through the region earlier. Cold
air aloft has been filtering in while a tighter pressure gradient is
in place. This is supporting winds of 25-35kts on the lake and by
the lakeshores so far. Additional colder air will filter into the
region this morning, which will help support more widespread gale
potential in the waters surrounding the Keweenaw and eastern Lake
Superior. Winds should mostly stay below 40 knots given the pressure
rises accompanying the colder air isn`t that strong. No changes were
made to the inherited Gale Warning for central and eastern Lake
Superior. In the western lake north and west of the Apostles, near
30kt winds should be expected, especially in the waters along the
Arrowhead where downsloping/drainage winds may provide for localized
gale force winds extending into the open lake. Winds will slowly
lighten from west to east tonight, but gale force gusts should
persist near and east of the Keweenaw at least into Thursday
morning. By Thursday late evening, winds below 20kts are expected
lake-wide.

Friday afternoon, another system will begin migrating eastward
through Manitoba. Tighter pressure gradient and a low level jet
ahead of the system`s cold front will move over the region, which
will help support increasing southerly flow through the frontal
passage on Saturday. The strength of the 925mb LLJ differs among the
various guidance packages, so its unclear how widespread gale
potential will be Friday night across the north-central. By Saturday
morning though, the airmass at 850mb is expected to be warmer than
the lake surface, so any stronger elevated winds will be difficult
to mix to the surface. Latest guidance suggests the cold front will
swing through by Saturday afternoon, followed by a period of strong
cold air advection (potentially 20C temperature drop at 850mb in 24
hours). At the same time, a stronger gradient is expected over the
lake. While the degree of cold air advection and wind speeds are
still a question, confidence in another gale event late Saturday
into Sunday night is increasing. Latest GEFS and EC ensemble runs
suggest 30-70% chance for gales while the NBM peaks near 50% east of
the Keweenaw.

&&

.MQT WATCHES/WARNINGS/ADVISORIES...
Upper Michigan...
None.
Lake Superior...
  Gale Warning until 7 PM EST /6 PM CST/ this evening for LSZ241-
     242-263.

  Gale Warning until 1 AM EST Thursday for LSZ243>251-264>267.

Lake Michigan...
None.

&&

$$

DISCUSSION...JTP
AVIATION...GS
MARINE...JTP