140
FXUS63 KMQT 222319
AFDMQT

Area Forecast Discussion
National Weather Service Marquette MI
619 PM EST Sat Nov 22 2025

.KEY MESSAGES...

- Light rain/snow mix presses east this evening followed by
  scattered lake effect rain/snow for the NW wind snowbelts
  through Sunday morning.

- Lake effect snow and wind may impact the Thanksgiving holiday
  weekend. Travelers and interested parties should continue to
  monitor the forecast as details become more clear over the
  coming week.

- There is a 50-60% chance for Gale Force and 20% chance for
  Storm Force winds/light freezing spray on Lake Superior during
  the middle of next week.

&&

.DISCUSSION...
Issued at 244 PM EST Sat Nov 22 2025

Early afternoon satellite imagery and RAP analysis reveals a mid-
level trough swinging through western Ontario extending south into
the Upper Great Lakes region. Closer to home, breezy south winds
have picked up as the pressure gradient has tightened ahead of a
weak sfc low. Mid to low level warm air advection has been the
primary forcing mechanism for a swatch of precip now moving through
the western UP. With antecedent dry air in place, not expecting much
more than light rain/snow showers as this progresses eastward
through the evening, mainly over the northern and eastern UP.
Tonight and into the morning hours of Sunday, the surface trough and
cold front dive SE into the Lower Lakes, veering winds to the NW and
ushering in 850mb temps between -5 to -7C. With an average Lake
Superior water sfc temp of ~+7C, this delta-T will be just enough to
kick off lake effect precipitation across the NW wind snowbelts.
However, model soundings are rather unimpressive, with meager lake
induced eq heights, and varying degrees of drying within the DGZ/sub-
cloud layer. Opting to leave in chance PoPs in the Keweenaw and
east, moreso the east, for low impact and non-accumulating (or
light) lake effect snow/rain/graupel showers are expected. With the
longer fetch across the eastern lake, lake effect may linger longer
in the east through daybreak tomorrow. Lake effect tapers off
tomorrow as a ridge begins to build over the Great Lakes once again,
allowing for quiet weather into Monday. This period will feature the
warmest temperatures of the week; look for highs in the 40s to and
perhaps closer to 50 for some Sunday, and well into the 40s and
lower 50s Monday.

More impactful weather returns during the mid to late week as two
troughs, one ejecting northeast from the southern Plains and another
from the Northern Rockies, phase in the Great Lakes Tuesday into
Wednesday. This synoptic evolution will support a deepening surface
low pressure in the vicinity of the Upper Great Lakes that moves
northeast into Quebec Wednesday night through Friday. The position
of this sfc feature and its exact track will have important
implications for surface sensible weather such as strong winds,
synoptically driven snowfall, and lake effect snow following its
passage, including where the heaviest snowfall axis occurs. The
general idea presented in all guidance packages though suggests that
synoptic rain will spread into the region Monday night and Tuesday
and then transition over to lake effect snow showers in the Tuesday
night to Wednesday timeframe. The recent suite of 12z ensembles and
their deterministic counterparts have come into better agreement on
the timing and evolution of the sfc low track, suggesting an overall
flatter upper level trough and a slower departure. Both the Euro ENS
and GEFS low-center locations suggest a ~990-1000mb sfc low
developing overhead the vicinity of Lake Superior or northern lower
MI by 12z Wednesday, the Euro a bit more progressive and east. With
the deterministic low track in both global models (especially the
GFS) being nearly right over the lake, the heaviest synoptic forcing
for snow may be largely displaced to our northwest, suggesting that
lake effect snow on the backside of the departing low will be the
main travel hazard heading Wednesday afternoon into Thanksgiving and
the following weekend. Ensemble probabilities for 24hr snow totals
>3" begin to ramp up 50-75% into Thursday over the northwest wind
lake effect snow belts, especially in the west half where
deformation/banding may occur in conjunction with lake
effect/enhanced precip. Probs for total snow >6" for the NW LES
belts increase above 75% through the weekend as cold NW flow
persists with the departing system. Another concern will be blowing
lake effect snow as NBM probs of NW gusts >40 mph increase above 50%
Wednesday with a low (<20%) chance for NW gusts >50 mph.

As we continue to monitor forecast trends through the coming days,
Thanksgiving travelers should maintain awareness of the forecast
should confidence in travel hazards increase.

&&

.AVIATION /00Z TAFS THROUGH 00Z SUNDAY/...
Issued at 619 PM EST Sat Nov 22 2025

MVFR conditions are expected through the night at the TAF sites as
low clouds spread into the area behind a cold front that was moving
through the U.P this evening. Winds will also become gusty (25-30kt)
at CMX. Northwest flow will keep lake effect clouds streaming into
the area but somewhat drier air should help limit cloud cover
towards morning, especially at IWD. Currently have the MVFR cloud
deck scattering out at CMX and SAW Sunday morning, however there is
quite a bit of uncertainly and it is possible (30-50% chance) the
MVFR conditions linger into the early afternoon hours. By late
afternoon probabilities for MVFR are negligible as onshore flow
decreases with winds turning southwesterly.

&&

.MARINE...
Issued at 244 PM EST Sat Nov 22 2025

Breezy southerly winds 20-30 kts are ongoing as a surface trough
extends across western Lake Superior. Tonight and through tomorrow
morning, the trough pushes east and winds veer NWerly behind the
surface cold front. Model soundings and ensemble probabilities favor
gales to 35 kts, with a few gales to 40 not out of the question,
from roughly midnight through 10AM EST. Have hoisted a Gale Warning
for portions of the central and eastern lake through this timeframe.
Significant wave heights build 7-12 ft east of the Keweenaw with the
heights waves closer to the eastern UP shoreline. NW gusts to 25 kts
hang on in the east half through tomorrow afternoon before lessening
below 15-20 kts lake wide and backing S-SW Monday.

Next week, a system is expected to move through the Great Lakes.
There`s still a number of questions about how this event will
evolve, including whether or not the surface low will deepen over
the region and how quickly it will move through the region. What is
certain though, is that the airmass moving in behind the system will
be notably colder, which increases the likelihood of gales in the
Tuesday night through Thursday night window. At this point, Storm
Force Winds and pockets of light freezing spray cannot be ruled out.
Given the clustering differences among the EC, Canadian, and GFS
ensemble membership, there`s varying degrees of potential outcomes
at this point. Given this, the latest Gale probabilities near 50%
and Storms near 25% make sense. As we move into next week, some of
this should improve and a clarity on anticipated conditions should
materialize.

&&

.MQT WATCHES/WARNINGS/ADVISORIES...
Upper Michigan...
None.
Lake Superior...
  Gale Warning from midnight tonight to 10 AM EST Sunday for
     LSZ249>251-266-267.

  Gale Warning from midnight tonight to 7 AM EST Sunday for
     LSZ265.

Lake Michigan...
None.

&&

$$

DISCUSSION...BW
AVIATION...NL
MARINE...BW