104
FXUS63 KMQT 220719
AFDMQT

Area Forecast Discussion
National Weather Service Marquette MI
219 AM EST Fri Nov 22 2024

.KEY MESSAGES...

- Scattered rain showers continue over the north tonight
through Friday.

- Light lake effect rain/snow showers are possible for mainly the
  east half of the U.P. tonight through Saturday. Little to no
  accumulations are expected.

- Active weather with chances for accumulating snow return next
  week. Temperatures trend to around to below normal for this
  time of year.

&&

.UPDATE...
Issued at 935 PM EST Thu Nov 21 2024

The band of rain showers that camped out over the central UP for
much of today is tapering off to lingering upslope rain showers
across the north-central UP with the surface low south of Lake
Michigan opening up to a surface trough and the midlevel low moving
towards the Mid Atlantic. Winds continue to fall back, but should
still be able to gust to around 20mph across much of the UP
tonight...particularly across our eastern zones where our pressure
gradient remains fairly tight. Winds to the west have been knocked
back slightly to align with latest observations and model guidance,
otherwise the forecast remains on track.

&&

.SHORT TERM /THROUGH TONIGHT/...
Issued at 322 PM EST Thu Nov 21 2024

Afternoon satellite imagery and RAP analysis show the sfc low has
made it just south of central Lake MI. Aloft, the mid level low is
analyzed over Lake Erie and OH with a ridge building in over the
Plains. Satellite imagery also highlighted some well defined
gravity waves earlier this afternoon in the low cloud deck near the
MN Arrowhead shores of Lake Superior. This is where some weak sfc to
850 mb CAA, low level fgen, and pressure rises resulted in northwest
katabatic winds. A few ship observations came in with storm force
winds gusting into the low to mid 50 kt range! SAR wind data also
shows that these winds extended into the northern open waters of
LSZ162. Outside the marine impacts, pressure falls this morning and
the tight pressure gradient resulted in northerly wind gusts up to
35 to 45 mph in the north half of the UP with 58 mph recorded at
Houghton County Memorial Airport. This ended up causing some power
outages this morning, but winds have already begun to weaken this
afternoon. North winds have fallen below 15 mph over the eastern
half of the UP with gusts still in the 15 to 25 mph range over the
west. North winds of 10 to 20 mph are expected for tonight.

Numerous showers have continued to dominate the central UP with
scattered showers over the west and isolated shower to dry
conditions over the east. Some clearing is even observed on
satellite over the Lake MI shores of Upper MI and northern Lower MI.
The sfc low is progged to descend over the rest of Lake MI into this
evening, dissipating tonight as the mid level low spins toward the
Atlantic Coast. This yields a eastward shift in the dominating band
of showers before some dry air moves in from the north. Model
soundings show the drier airmass intruding above the the 5-7 kft
level, diminishing shower coverage and overall QPF. That said,
scattered upslope and lake enhanced showers are expected tonight
over the north. An additional few hundreths to 0.15 inches are
expected over the western 2/3 of Upper MI this afternoon through
tonight. Up to 0.6" of additional rain is forecasted over portions
of Baraga and Marquette Counties aided by the upslope flow; most of
the QPF is expected to fall during the next 6 hours. Overall, wet
snow and rainfall over the past 24 hours has brought around 0.5 to 2
inches of liquid precip which should help improve drought conditions
across the UP.

Otherwise, temps currently in the upper 30s to mid 40s are expected
to settle into the mid 30s to low 40s tonight.

&&

.LONG TERM /TONIGHT THROUGH THURSDAY/...
Issued at 218 AM EST Fri Nov 22 2024

The long-term pattern looks to remain fairly active with late Fall
weather FINALLY looking to dominate the period as multiple
shortwaves impact the Upper Midwest and U.P. the next several days.
This pattern will bring near normal to slightly below normal
temperatures for this time of year as well as multiple shots of
precipitation, with rain this weekend transitioning to snow by next
week; we could even see some lake-effect snowfall across the area
come Thanksgiving Day, which could throw a wrench into the travel
plans for some. Additional details follow below.

As a weak shortwave moves from north to south across Lake Superior
tonight through Saturday, expect a reinvigoration of lake-effect
precipitation across the northwest snow belts, with the lake-effect
rain slowly transitioning to lake-effect snow from west to east as
the colder air behind the low slowly pushing eastward across the
area. With temperatures remaining near or slightly above freezing
across most of the area tonight through Saturday, not much snowfall
is expected to accumulate, save for over the higher terrain of the
north central (such as the Michigamme Highlands); we could see a
light dusting over there, mainly over the grassy areas as
temperatures get to around to slightly below freezing. In addition,
with inversion heights only getting to around -7 C, we may have
times were we don`t have a transition to snowfall but instead a
transition to freezing drizzle, particularly over the interior west
where temperatures could dip below freezing late tonight. Should any
freezing drizzle accumulate, expect for there to only be a trace of
ice, mainly on elevated surfaces as temperatures should still be
fairly warm given the above freezing temperatures expected today.
Overall, any snow or freezing drizzle impacts over the western U.P.
tonight into Saturday morning should be null (no impacts are
expected). As weak ridging builds in Saturday night into Sunday,
expect the last of the lake-effect snow to end over the eastern U.P.
early Sunday morning.

Our next chance for precipitation looks to come Sunday night/Monday
as a shortwave ejecting from the Northern Rockies/Alberta looks to
phase with another shortwave low ejecting off of the Colorado
Rockies. While there is high uncertainty in regards to the track of
the phasing shortwaves (and thus the amount of precipitation that we
will see across our area), deterministic and ensemble guidance all
agree that precipitation of some kind will be possible beginning
Sunday night/Monday. While we may see some rain or even freezing
rain over the west half initially, expect the changeover to all snow
later in the event as colder air from behind the northern shortwave
makes its way across the Upper Midwest. This shot of cold air will
fuel lake-effect snowfall as we head into the middle of next week.

After this system, ensemble guidance shows temperatures remaining
below freezing throughout the rest of the extended period and beyond
as additional cold air and Clipper shortwaves impact Upper Michigan.
The shortwaves and cold air could bring some much needed snowfall to
the snow belts near Lake Superior late next week into early
December. Indeed, one of these shortwaves could move through on
Thanksgiving; should it do so, we could see some road hazards such
as accumulating snowfall and significantly reduced visibilities in
spots along the snow belts near Lake Superior, which could cause
some problems for those needing to travel on Thanksgiving Day.

&&

.AVIATION /06Z TAFS THROUGH 06Z SATURDAY/...
Issued at 1241 AM EST Fri Nov 22 2024

The coverage of rain showers and drizzle will continue to
diminish across the area early this morning. Mainly IFR
conditions are expected to persist through 00Z Saturday; however
there is around a 30% chance that LIFR conditions at SAW and
IWD early this morning. Conditions will slowly improve to MVFR
after 00Z Sat. Northerly winds of 10-20 kt will persist through
the TAF period.

&&

.MARINE...
Issued at 218 AM EST Fri Nov 22 2024

Winds continue to weaken over the western half of the lake early
this morning as northerly winds of 20 to 25 knots continue across
the eastern half today before backing to the northwest tonight. The
winds eventually weaken to 20 knots or less Saturday evening as weak
ridging moves in from the west. The lighter winds look to remain
across the area until Monday, when a Northern Rockies/Clipper
shortwave low phasing with a shortwave low lifting from Colorado
into the Great Lakes region brings cold air advection and
northwesterly winds of 20 to 30 knots back across the lake Monday
into Tuesday morning (the NBM shows up to a 20% chance of gales up
to 35 knots or greater for this time period). Once the cold air
advection weakens, expect the winds to drop to 20 knots or less
again late Tuesday.

&&

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

&&

$$

UPDATE...LC
SHORT TERM...Jablonski
LONG TERM...TAP
AVIATION...RM
MARINE...TAP