FXUS63 KMQT 150737

Area Forecast Discussion
National Weather Service Marquette MI
337 AM EDT Mon Oct 15 2018

.SHORT TERM...(This evening through Monday)
Issued at 244 PM EDT SUN OCT 14 2018

Cloud cover has steadily thickened as an upper level system
continues to dive southeast across the Upper Midwest this
afternoon. Ahead of this system was a quasi-stationary boundary
drifting north with moisture aloft helping to expand the light
rain/snow showers across the Upper Peninsula. T/Td spreads have
slowly diminished with the profile moistening, and wet-bulbing
down will likely bring precip at onset as light snow but could mix
with rain as well. Surface flow will remain northwesterly for
much of the area this evening. Trough axis upstream will continue
to pivot east towards the region, allowing some better forcing to
arrive overnight and could further enhance the precip shield.
Thermal profiles overnight indicate most of the precip will fall
as snow tonight, with snow-ratios slowly increasing to the lower
teens. This coupled with QPF progged to be through Mon between
0.05 and 0.25 for the southeast counties, would produce snowfall
totals around 1 to perhaps 2 inches in a few isolated locations
thru Mon afternoon. The favored upslope locations from northwest
flow could see the better snow showers after midnight through Mon
midday, before the shortwave begins to lift northeast of the area
and pull the deeper moisture away from the Upper Peninsula. Temps
tonight will fall into the mid/upr 20s away from the lakes, and
lower 30s closest to Lake Superior. Then for Mon, with continued
thick solar shielding, expect temps to struggle to warm beyond the
mid/upr 30s for the central/western Upper Peninsula, meanwhile
further east temps could warm to around 40.

.LONG TERM...(Tuesday through Sunday)
Issued at 336 AM EDT MON OCT 15 2018

The omega block over the eastern Pacific will keep the upper air
pattern stagnant across the CONUS, leaving us under the influence of
persistent troughing and northwest flow through much of the week. As
has been advertised for days now, this means we will see multiple
waves dig across the Upper Great Lakes ushering in multiple rounds
of colder air at times and chances for lake effect snow and rain
showers periodically. We will see a brief break from the well-below
normal temperatures with a warm up towards the end of the week, but
then the return of more wintry precipitation and cooler temperatures
are expected for the weekend.

Tuesday through Wednesday, an initial shortwave will dig south
across the region pushing a backdoor cold front south across the
Upper Peninsula late Tuesday into Wednesday. There isn't much deep
moisture for this front to work with, so don't expect much in the
way of precipitation on Tuesday. Behind the cold front, a
reinforcing shot of colder air aloft will dig south and allow the
return of lake effect snow showers across the northwest wind snow
belts Tuesday night into Wednesday. Wednesday will be a cold day,
with temperatures primarily in the 30s. The combination of cold
ambient temperatures and brisk northwest winds will make it feel
like temperatures are in the teens Wednesday morning and 30s by the
afternoon. As temperatures warm a bit Wednesday afternoon, locations
near the shoreline of the Great Lakes will likely see lingering lake
snow showers transition over the rain showers. Wednesday night warm
air advection begins to return, shutting down any lingering lake
effect precipitation from west to east.

Thursday through Friday, the return of the above mentioned warm air
advection will be a nice break from the unseasonably cold
temperatures we've experienced as of late. In fact, by Thursday we
should see an abundance of sunshine with temperatures climbing into
the low to mid 50s, which is near normal for this time of year. With
a strengthening pressure gradient means that we will continue to
maintain breezy conditions, but with southwesterly flow across the
Upper Peninsula. On Friday, a potent shortwave will begin to dig
south across the Upper Mississippi Valley. This will begin the
eastward push of a cold front. Medium range models are in good
agreement with the timing of the front pushing into western Upper
Michigan early Friday afternoon, central Upper Michigan mid-Friday
afternoon, and eastern Upper Michigan late Friday afternoon/early
evening. However, they do diverge on precipitation along the front.
Expect some light rain ahead of the front on Friday, but confidence
is low in regards to the coverage. Behind the front, models diverge
on the strength of cold air advection and thus how quickly the onset
of trailing lake effect precipitation will be.

This weekend, lake effect snow showers are expected across the north
and northwest snow belts. Difficult right now to say the timing of
the lake effect across these belts, as models diverge on the arrival
and speed/strengthen of yet another shortwave delivering a
reinforcing shot of colder air. Early next week, we will see another
brief warm up ahead of yet another wave digging south from Canada.

.AVIATION...(For the 06Z TAFS through 06Z Monday night)
Issued at 143 AM EDT MON OCT 15 2018

Cigs near or just above the MVFR threshold are expected overnight
that will gradually lift to VFR Monday morning. Any snow at KSAW
will depart early in the TAF period. Otherwise, gusty west winds
will prevail over the west at KIWD and KCMX with some increase in
rain or snow showers at KCMX into Monday morning. However, no vsby
reductions are expected with the precipitation.

.MARINE...(For the 4 PM Lake Superior forecast issuance)
Issued at 244 PM EDT SUN OCT 14 2018

West winds to around 25 knots early will diminish into tonight as
ridging briefly builds into the area. However, Monday into Monday
night winds will become southwesterly and veer northwesterly by
Tuesday as a low pressure system tracks north of the Upper Great
Lakes. Gales will possible, especially Monday night. However, since
there is some uncertainty with the stability and amount of mixing
and the impact on wind values. With colder air clipping Lake
Superior behind this system, expect northwest winds 20 to 30 knots
to hold on through Wednesday.

Upper Michigan...
Lake Superior...
Gale Watch from this evening through Tuesday morning for LSZ162-

Lake Michigan...


SHORT TERM...Beachler
LONG TERM...Ritzman
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