Storm Warning 5, NWS Duluth, MN

Area Forecast Discussion
National Weather Service Duluth MN
1137 AM CST Tue Dec 3 2024

.KEY MESSAGES...

- Snow will begin this afternoon across the Northland, with the
  heaviest snow occurring in the tip of the Arrowhead. Snow
  totals up to 7 inches possible in the higher terrain. Lake
  effect snow will linger behind the system.

- On the back end of the system, a few snow squalls are possible
  in far northern Minnesota, and strong winds are expected along
  the North Shore. Temperatures will decrease to up to 15
  degrees below normal.

- A couple more chances for snow across the Northland will
  return this weekend.

&&

.DISCUSSION...
Issued at 221 AM CST Tue Dec 3 2024

A clipper will arrive today and bring light snow across
portions of northeast Minnesota and northwest Wisconsin. The tip
of the Arrowhead will receive the most snow due to a combination
of lake and terrain enhancement with flow out of the southwest
this afternoon and evening. Totals of 4 to 7 inches are expected
at the tip of the Arrowhead by Wednesday morning, with the
highest at higher elevations.

On Wednesday, the low center will have passed, but northwest
flow and strong cold air advection will lead to multiple
phenomena. First, cold air being advected aloft will increase
low level lapse rates and, accompanied by strong winds and cold
air advection, could lead to scattered snow squalls across the
Borderlands to inland Arrowhead. Quickly reducing visibilities
and locally heavy snow could lead to dangerous driving
conditions. Despite this, additional snow accumulations from
these snow squalls will be less than an inch. Second, lake
effect snow will ramp up once again across Iron County as the
cold air will be upwards of -15C across relatively warm waters
(temperatures in the upper 30s and lower 40s) of Lake
Superior. From Wednesday afternoon to Thursday afternoon, up to
6 additional inches are possible from lake effect snow. Third,
strong winds aloft from a tightening pressure gradient will be
able to mix down to the surface with the increasing low level
lapse rates. Widespread winds up to 35 mph are expected. Wind
gusts exceeding 40 mph are possible in the Brainerd Lakes area
and along the North Shore. Confidence is higher for these gusts
along the North Shore due to katabatic winds. These areas could
need a Wind Advisory starting early Wednesday afternoon.
Finally, the advection of cold air into the area will lower
temperatures for Wednesday night through Thursday night. Highs
on Thursday will be in the upper teens with subzero temperatures
overnight. Combined with the gusty winds Wednesday night, wind
chills as low as -20 F are possible.

A couple of shortwaves will move through this weekend, bringing
more chances for snow. Details of these systems, such as track
and timing, are still uncertain.

&&

.AVIATION /18Z TAFS THROUGH 18Z WEDNESDAY/...
Issued at 1131 AM CST Tue Dec 3 2024

Clipper system dropping southeastward spreads heavier snowfall
into the Iron Range and Arrowhead northward over the next 2 to 4
hours. Expect LIFR to IFR visibilities and MVFR ceilings within
this 6 to 8 hour snowfall event, exiting last through the
Arrowhead around 6Z Wednesday. Southwest winds shift westerly
behind the clipper this evening and remain breezy around 20
knots through early Wednesday morning. From 09-15Z Wed, expect
another wind shift to northwesterly and a quick increase in wind
speeds lasting beyond this TAF period. Blowing snow is likely
after 15Z Wed and creating MVFR visibilities at area terminals
mainly along and north of U.S. Highway 2.

&&

.MARINE /FOR NEAR SHORE WATERS OF WESTERN LAKE SUPERIOR/...
Issued at 221 AM CST Tue Dec 3 2024

Increasing winds out of the southwest ahead of a clipper will
lead to gusts hazardous to small craft starting this afternoon.
An occasional gale is possible out in the Apostle Islands
tonight, but the majority should remain out in the open waters,
so have not issued a gale warning for the Apostle Islands at
this time. Winds will further increase out of the northwest
after the clipper has passed, and widespread gales are expected
Wednesday afternoon through Wednesday night. There is around a
20 percent chance for storm force gusts out over the open
waters and around the Apostle Islands. Will continue to monitor
to see if an upgrade will be needed.

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 midnight CST tonight for MNZ012.
     Winter Storm Warning until midnight CST tonight for MNZ021.
WI...None.
MARINE...Small Craft Advisory until noon CST Wednesday for LSZ121-
     140>148-150.
     Gale Warning from noon Wednesday to 9 AM CST Thursday for
     LSZ121-140>148-150.

&&

DISCUSSION...KML
AVIATION...NLy
MARINE...KML

Hazardous Weather Outlook...UPDATED
National Weather Service Duluth MN
1113 AM CST Tue Dec 3 2024

MNZ010>012-018>021-025-026-033>038-WIZ001>004-006>009-041715-
Koochiching-North St. Louis-Northern Cook/Northern Lake-
North Itasca-Central St. Louis-Southern Lake/North Shore-
Southern Cook/North Shore-North Cass-South Itasca-South Cass-
Crow Wing-Northern Aitkin-South Aitkin-Carlton/South St. Louis-
Pine-Douglas-Bayfield-Ashland-Iron-Burnett-Washburn-Sawyer-Price-
1113 AM CST Tue Dec 3 2024

This Hazardous Weather Outlook is for portions of northeast
Minnesota and northwest Wisconsin.

.DAY ONE...This afternoon and Tonight

A clipper system will bring 2 to 8 inches of snow to the
Minnesota Arrowhead this afternoon and tonight. Elsewhere, less
than 2 inches of snowfall is expected. Snowfall rates are forecast
to be highest this afternoon and evening where more than 1 inch
per hour rates are possible and could impact the evening
commute. A Winter Storm Storm Warning is in effect for southern
Cook County from 2 PM through midnight tonight. Winter Weather
Advisory is in effect for inland Cook and Lake counties.

.DAYS TWO THROUGH SEVEN...Wednesday through Monday

Snow showers are possible across the Minnesota Arrowhead
Wednesday, with an additional 0.5 inch to 1 inch of snow
accumulation possible. Lake Effect Snow showers are expected
across the South Shore Wednesday through Thursday, with 2 to 7
inches of snowfall across portions of Bayfield, Ashland and Iron
counties in northern Wisconsin.

A period of strong northwesterly winds is expected Wednesday
through early Thursday, with wind gusts of 40 to 50 mph possibly
to 60 mph along the North Shore, as colder air spreads across the
area. Low temperatures Thursday and Friday morning will be in the
single digits areawide.

.SPOTTER INFORMATION STATEMENT...

Snow spotters are requested to report their snowfall measurements
to the National Weather Service.

LSZ121-140>148-150-041715-
Bayfield to Oak Point WI-Grand Portage to Grand Marais MN-
Grand Marais to Taconite Harbor MN-
Taconite Harbor to Silver Bay Harbor MN-
Silver Bay Harbor to Two Harbors MN-Two Harbors to Duluth MN-
Duluth MN to Port Wing WI-Port Wing to Sand Island WI-
Sand Island to Bayfield WI-Oak Point to Saxon Harbor WI-
Outer Apostle Islands Beyond 5 NM from Mainland-
1113 AM CST Tue Dec 3 2024

This Hazardous Weather Outlook is for portions of Lake Superior
and the Nearshore waters of western Lake Superior.

.DAY ONE...This afternoon and Tonight

Winds increase out of the southwest this evening, with wind gusts
across western Lake Superior up to 33 kts and wave heights of 5
to 8 ft through early Wednesday.

.DAYS TWO THROUGH SEVEN...Wednesday through Monday

Winds veer to the northwest for Wednesday and Thursday as a
clipper system moves through the region. Hazardous conditions are
likely across much of western Lake Superior, with a 90 percent
chance for widespread strong gale force winds Wednesday into
early Thursday morning. Storm force gusts are also possible.
Additionally, wave heights of 5 to 12 ft are expected.

Wolfe

More information may be obtained at the following web address:
http://www.weather.gov/duluth