215
FXUS63 KDLH 060011
AFDDLH

Area Forecast Discussion
National Weather Service Duluth MN
611 PM CST Wed Feb 5 2025

.KEY MESSAGES...

- Widespread snow returns this afternoon and departs Thursday
  morning. Snow accumulation of 2-6 inches expected across the Northland.
  Locally higher amounts are possible along the North Shore.

- Gusty westerly winds are possible Thursday into Friday, with
  gusts of 30-40 mph possible, especially along both the North
  and South Shores.

- There is a 10-20 percent chance of snow squalls Thursday over the
  Arrowhead and portions of north-central Minnesota.

- Another chance for snow arrives Saturday, with best chance for
  accumulations over 4 inches along and south of US-2.

&&

.DISCUSSION...
Issued at 246 PM CST Wed Feb 5 2025

Current Conditions:

Surface high pressure is retreating to the east with southerly
flow streaming across the region. Radar depicts some snow
showers to the west migrating across MN. This snow is most
likely not making it to the ground just yet due to dry air in
the lower levels. Model soundings show a dewpoint depression of
around 20C around 3000 ft which will take several more hours to
saturate out.

Snowfall Setup for tonight:

This evening a surface low develops over SE Manitoba and moves into
Ontario. Warm air advection ramps up in response to this development
promoting increased forcing for ascent and snow showers. Model
soundings depict a small DGZ aloft falling into a mid level warm
nose. The depth of the warm nose and the temperature profile below
the nose are still contested pieces of the puzzle among the
deterministic guidance. The potential pitfall of the forecast is
the depth of the DGZ below the warm nose. The consensus of the
models is that we will be teetering along the edge of -12C which
will introduce some riming into the ice crystals. However if we lean
more into a colder solution than our SLRs will increase jumping our
snow totals to the higher end solutions of greater than 6 inches.

Snow amounts and timing tonight/tomorrow morning:

This forecast package sees a slight uptick in QPF as we siphon off a
little bit of gulf moisture. However, looking at ALPW our main
moisture source looks to be the Pacific. The track of the system has
also slightly shifted further north. The higher amounts of 3 to 6
inches are now favored for northern MN with NW WI more in the 2 to 4
inch range. Upstream satellite shows some convective features with
cellular clouds moving into the Red River Valley. Heavier
snowfall rates this evening and overnight will be expected with
rates of 0.5 to 0.75 inches and hour with some isolated areas
seeing 1 inch per hour rates. The system is fairly progressive
and we will see the bulk of the system exiting tomorrow morning.
Lastly, this updated forecast package will see an upgrade to a
Winter Storm Warning for southern Cook County where they have a
60-70% chance of seeing greater than 7 inches.

Thursday Breezy:

Thursday will see a blast of cold air out of the west as a cold
front sags southeast through the day. Gusty winds are expected with
gusts in excess of 35 mph. With fresh snow on the ground this may
lead to blowing snow at times. We do manage to build in some weak
instability to generate snow showers in the afternoon. The snow
squall parameter isn`t quite impressive due to low level lapse rates
not being steep enough. At best it looks like a 10-20% chance that a
few squalls develop.

Weekend Snow System:

The next big player on the horizon is a storm brewing for the
weekend. An upper level trough digs into the Intermountain West with
a strengthening jet across the Midwest. A large corridor of
FGEN will move across the Upper Midwest helping to promote some
heavy banded snow. The majority of the guidance is keeping the
bulk of the moisture and energy just south of our region. But
its worth noting that the Euro solutions show a slightly further
northern solution which would impact locations south of US 2.

&&

.AVIATION /00Z TAFS THROUGH 00Z FRIDAY/...
Issued at 610 PM CST Wed Feb 5 2025

Snow showers will move through the region tonight, increasing in
coverage through the evening hours. Expect snowfall rates of 1/2
to 1 inch per hour. By early Thursday morning, snowfall
accumulations of 3-5 inches are possible at forecast terminals.
VFR cigs will fall to MVFR as snow showers arrive. Vis will also
fall in heavier snow showers, to below 1SM. Southeasterly winds
at 8-10kts with gusts of 14-18kts will veer to the southwest
overnight. Snowfall ends from southwest to northeast Thursday,
with winds increasing from the west. Gusts up to 30kts are
possible through the day. Blowing snow will be possible. Expect
little improvement in cigs, with MVFR heights remaining through
the day.

&&

.MARINE /FOR NEAR SHORE WATERS OF WESTERN LAKE SUPERIOR/...
Issued at 246 PM CST Wed Feb 5 2025

Low pressure over the central Plains today. Light northerly winds
are backing southeasterly this afternoon and will gradually increase
in speed as the surface low approaches. Conditions will become
hazardous to small craft this evening due to wind gusts of 25 to 30
knots and wave heights of 2 to 7 feet. Gusts will continue to
increase early Thursday morning with gales becoming likely by 6 AM.
Winds will veer westerly Thursday morning and northwesterly by
Thursday evening. Gales will subside quickly late Thursday night as
the low pressure system departs. There is a risk of heavy freezing
spray Thursday as colder air pours into the region. The system will
also bring snow which will reduce visibility to less than 1/2 mile
at times.

For the open water discussion, refer to the NWS Marquette Area
Forecast Discussion at weather.gov/mqt.

&&

.DLH WATCHES/WARNINGS/ADVISORIES...
MN...Winter Weather Advisory until 6 AM CST Thursday for MNZ010>012-
     019-020.
     Winter Weather Advisory until 6 AM CST Thursday for MNZ018-025-
     026-034>038.
     Winter Storm Warning from 9 PM this evening to 6 AM CST
     Thursday for MNZ021.
WI...Winter Weather Advisory until 6 AM CST Thursday for WIZ002-003-
     008.
     Winter Weather Advisory until 6 AM CST Thursday for WIZ001-006-
     007.
MARINE...Small Craft Advisory from 10 PM this evening to 6 AM CST
     Thursday for LSZ140>148-150.
     Gale Warning from 6 AM Thursday to midnight CST Thursday night
     for LSZ140>148-150.

&&

$$

DISCUSSION...Britt
AVIATION...HA
MARINE...Britt