904
FXUS63 KMQT 221719
AFDMQT

Area Forecast Discussion
National Weather Service Marquette MI
1219 PM EST Fri Nov 22 2024

.KEY MESSAGES...

- 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.

&&

.SHORT TERM /THROUGH TODAY/...
Issued at 1219 PM EST Fri Nov 22 2024

In the wake of yesterday`s rainfall event, continued northerly flow
off Lake Superior with abundant low level moisture has supported
mostly cloudy skies and some terrain aided drizzle/light rain. The
precip appears mostly confined to central Upper Michigan, the
Keweenaw and the Gogebic Range per webcams, but I wouldn`t be
surprised if pockets of drizzle were experienced elsewhere. Daytime
highs have clocked out in the upper 30s to low 40s.

More of the same is expected as we progress through the night. A
brief period of cold air advection on the heels of a weak shortwave
overnight will help lower and reinforce a low level inversion,
trapping moisture and cloud cover over the forecast area. This will
also support more sustained, albeit still light and scattered, lake
effect shower activity mainly over the east. Overnight lows look to
bottom out in the 30s.

&&

.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 /18Z TAFS THROUGH 18Z SATURDAY/...
Issued at 1209 PM EST Fri Nov 22 2024

Abundant low level moisture will sustain MVFR and IFR ceilings
through out this TAF period under upslope northerly to northwesterly
flow. MVFR appears most prevalent, but IFR ceilings will be possible
at times tonight given the lowering inversion. Drizzle/light rain
and MVFR visibilities will be possible today, mainly at KSAW and it
can`t be ruled out at KCMX. Gusty winds near 20kts from the north to
northwest are also expected at KCMX and KSAW this afternoon.

&&

.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.

&&

$$

SHORT TERM...JTP
LONG TERM...TAP
AVIATION...JTP
MARINE...TAP