562
FXUS63 KMQT 081736
AFDMQT

Area Forecast Discussion
National Weather Service Marquette MI
1236 PM EST Wed Jan 8 2025

.KEY MESSAGES...

- A fluffy inch or two is possible this afternoon from
  Marquette/Harvey to K.I./Little Lake/Skandia before the lake
  effect snow ends by this evening.

- Expect below normal high temperatures today before
  temperatures trend warmer Thursday through the weekend.

- There are no indications for any major winter systems to
  impact Upper Michigan in the next seven days.

&&

.SHORT TERM /THROUGH TONIGHT/...
Issued at 1235 PM EST Wed Jan 8 2025

Lake effect snow showers over the north wind snow belts are winding
down this afternoon as surface high pressure ridging continues to
move through the Upper Midwest and Upper Great Lakes region. As
winds die down and turn southwest/southerly this evening, expect the
lake effect cloud cover to scatter out by the overnight hours. While
highs this afternoon may be limited to the upper teens to lower 20s,
lows tonight could get quite chilly; while I did a mix of
NBM/NBM10th percentile for lows tonight on decrease only from the
previous forecast, the temperatures may not be cold enough as
longwave radiation will easily escape out of the atmosphere. Thus,
while I expect temperatures to get down to around zero to the
negative single digits in the interior areas tonight, we could see
some of the cold spots drop down closer to -10F, particularly over
the interior west and far east next closer to the Soo.

With one of our NWS employees reporting up to around 5" of snowfall
in Harvey since this morning, we could see an additional fluffy inch
or two from Marquette/Harvey all the way to K.I./Little Lake/Skandia
this afternoon before the last of the lake effect peters out.
Therefore, watch out for reduced visibilities along U.S. 41 from
Marquette to Skandia this afternoon, and give some extra space to
the car in front of you in case you need to make a quick stop.

&&

.LONG TERM /TONIGHT THROUGH TUESDAY/...
Issued at 334 AM EST Wed Jan 8 2025

The extended forecast starts with a brief period of mid level
ridging moving east over Upper MI with a sfc high just out ahead of
it. This results in a southerly shift in low level flow and lifts
residual LES out over Lake Superior the rest of tonight and clears
skies. Temps will be the forecast challenge during the overnight
period as mid to high level clouds are possible noting some moisture
aloft increasing in the model soundings. But, where lake effect
clouds are able to clear out quicker, near calm conditions with
850mb temps still below -10C and some subsidence could allow for sfc
temps to drop near or below 0. Wind chills near -10 are forecasted
for the interior west by Thursday morning as the pressure gradient
increases yielding an uptick in winds.

With WAA then into Thursday, highs will be warmer than today,
peaking in the low to mid 20s. Clouds increase from the west ahead
of the next shortwave and associated frontal boundary. Thursday
night through Friday, a mid level trough over Manitoba moves to far
northern Ontario, sending a shortwave into the Upper Great Lakes.
Initially, precip looks to be primarily f-gen driven as better PVA
holds off until later in the day Friday. Accumulations also are not
expected to be much as LREF probabilities of at least 0.01" of QPF
only range between 30-50% from the frontal boundary. A dusting to
0.2" of snow is expected. There continues to be front timing
differences with the ARW/HRRR/RAP bringing precip into the west as
early as 18-21Z on Thursday while the NAM/ECMWF/GFS hold off until 0-
6Z Friday. Some lake enhancement off Lake Michigan is possible
Thursday night into Friday ahead of the frontal boundary, but
accumulations from this would also be low at around 0.5" or less
(mainly outside our CWA over Mackinac county). What does have a
better shot at yielding some snow is the colder airmass filtering in
behind the trough into the weekend. 850mb temps drop to -13C to -16C
for Friday night and Saturday, and with Lake Superior around 4C, the
16-20C delta-Ts will be sufficient for some light LES into the
weekend. Little to no impacts are expected as 12HR accumulations
should remain light, ~1" or less over the northwest wind snow belts
Friday into Saturday. Otherwise lows Thursday night will be warmer
in the teens to low 20s and Friday highs will be in the 20s. The
rest of the weekend looks to settle closer to normal with highs in
the upper teens to mid 20s and lows in the teens to single digits
near 10.

The next system to impact the region is a clipper low Sunday into
Monday. As a mid level closed low develops over northern
Ontario/Manitoba Saturday night and Sunday, another shortwave moves
from the Northern Plains to the southern end of the Great Lakes
Basin. Ensemble guidance is still struggling to agree on the track
of the resulting clipper low Sunday into Monday, but confidence in
some widespread light snow is increasing. Probabilities of at least
1" per 24 hours is around 20-50% across the UP. This system does
bring an uptick in moisture, which will aid in the trailing LES
likely to follow into early next week given the colder airmass
behind the clipper system.

&&

.AVIATION /18Z TAFS THROUGH 18Z THURSDAY/...
Issued at 1208 PM EST Wed Jan 8 2025

Lake effect cloud cover and snowfall dwindles this afternoon as high
pressure moves overhead and switches the winds to the
southwest/south. With that occurring, expect conditions at the TAF
sites to improve from generally MVFR to VFR by late this
afternoon/early this evening. The VFR conditions are expected to
continue tonight through Thursday morning.

&&

.MARINE...
Issued at 334 AM EST Wed Jan 8 2025

Northerly winds this morning have settled to 20 kts or less for the
most part, and will continue to taper down as weak high pressure
shifts southeast over the Upper Great Lakes. As a result, winds back
southwest this afternoon through this evening from west to east.
Southwest winds become south-southwest into Thursday, increasing to
around 20 kts as a low pressure trough approaches the lake from the
west; some gusts up to 25 kts are possible over the east half of the
lake during the day Thursday (40-60% chance). A cold front passes
over the lake Thursday night into Friday, veering winds to the
northwest. That said, winds are expected to remain 20 kts or less
the remainder of the forecast period. Northwest winds eventually
veer north for Sunday, backing northwest again for early next week.

&&

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

&&

$$

SHORT TERM...TAP
LONG TERM...Jablonski
AVIATION...TAP
MARINE...Jablonski