FXUS63 KDLH 112026
AFDDLH

Area Forecast Discussion
National Weather Service Duluth MN
226 PM CST Wed Dec 11 2024

.KEY MESSAGES...

- Blustery northwest winds and an Arctic airmass create wind
  chills from 20 to 35 below zero tonight into Thursday morning.

- Moderate lake effect snowfall is expected to continue for
  northern Bayfield and Iron Counties into tomorrow morning.

- Temperatures warm to normal Friday and well-above normal for
  the weekend when a wintry mix is forecast Saturday in
  northwest Wisconsin and far eastern Minnesota.

&&

.DISCUSSION...
Issued at 220 PM CST Wed Dec 11 2024

Deep eastern U.S. troughing from low pressure centered in
northern Quebec keeps northwesterly flow over the central U.S.
as an Arctic airmass dropped southward from the southern
Canadian Plains earlier today. The tightened pressure gradient
has produced northwest winds gusting 25-35 mph today and these
conditions are expected to last into tonight as air temperatures
drop into the single digits to low teens below zero areawide.
For these cold wind chills when combining the air temperatures
and gusty winds, the ongoing Cold Weather Advisory was expanded
in area into northern Cass and Aitkin Counties and the Advisory
was begun this afternoon to cover all PM hours today and through
mid-Thursday morning.

Along the South Shore, surface observations and trained spotters
report continued light to periodically moderate lake effect
snowfall in the Bayfield Peninsula and northern Iron Counties.
Another 2 to 5 inches is expected through early tomorrow morning
for these high terrain South Shore locations so the ongoing
Winter Weather Advisories (Bayfield/Ashland) and Winter Storm
Warning (Iron) were continued this afternoon.

As high pressure enters the region Thursday night, clearing
skies, still below zero dewpoints, and winds becoming calm will
create another round of very chill temperatures by Friday
morning. While there could be a need for a second Cold Weather
Advisory for Thursday night into Friday morning, the calm winds
and forecast air temperatures into the mid-teens below zero 
resulted in no headline issuance for this time period with this 
forecast package.

Southwesterly return flow sets up Friday to create near-normal
temperatures to end this work week. Further warming occurs this
weekend, to bring temperatures back into the 30s. Ensemble
global cluster analysis points to high confidence in a low
pressure system lifting northeastward from the Central U.S.
Plains by Saturday mid-day. The favored track of the low
pressure center runs through IA/S WI/N IL at this time which
keeps the Northland precip-limited, but on the cooler side for
mainly snowfall to be favored for anything that does fall in
northwest WI and far eastern Minnesota. While the forecast does
not currently call for this scenario right now, there is a
15-25% chance of some mixed precip creating a freezing rainfall
scenario for northwest Wisconsin Saturday. The warm temperatures
last into Monday, but drop back towards normal Monday night into
Tuesday. Another round of colder Canadian air could (30-50%
chance) drop southward again by mid-next week to create low
temperatures near the zero degree mark.

&&

.AVIATION /18Z TAFS THROUGH 18Z THURSDAY/...
Issued at 1131 AM CST Wed Dec 11 2024

An Arctic airmass will remain overhead through this TAF period,
creating blustery northwester winds. Expect periods of MVFR
visibility today due to blowing snow. South Shore lake effect
snow showers last through Thursday 12Z, along with localized
snow showers in the far northern Minnesota regions, to create
areas of IFR conditions.

&&

.MARINE /FOR NEAR SHORE WATERS OF WESTERN LAKE SUPERIOR/...
Issued at 157 PM CST Wed Dec 11 2024

An Arctic airmass overhead this afternoon lingers through
Thursday night. These very cold temperatures with open seas and
gusty northwest winds create concerns for Heavy Freezing Spray
over much of the western waters tonight into Thursday morning.
Gale Warnings go into effect this evening as the strongest
northwest winds gusting to 40 knots downslope off the North 
Shore near and northeast of Silver Bay into tomorrow. Conditions
hazardous to small craft are expected into Thursday evening so a
period of Small Craft Advisories are likely after the current
headlines expire tomorrow.


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

&&

.DLH WATCHES/WARNINGS/ADVISORIES...
MN...Cold Weather Advisory until 10 AM CST Thursday for MNZ010>012-
     018>021-025-026-035-037.
WI...Cold Weather Advisory from 10 PM this evening to 10 AM CST 
     Thursday for WIZ001>004-008-009.
     Winter Weather Advisory until 6 AM CST Thursday for WIZ002-003.
     Winter Storm Warning until 6 AM CST Thursday for WIZ004.
MARINE...Small Craft Advisory until 10 AM CST Thursday for LSZ121-
     143>145.
     Small Craft Advisory until 4 PM CST this afternoon for 
     LSZ140>142.
     Gale Warning until 10 AM CST Thursday for LSZ140>142.
     Heavy Freezing Spray Warning until 6 AM CST Thursday for 
     LSZ145>147.
     Small Craft Advisory until 4 PM CST Thursday for LSZ146>148-
     150.
     Heavy Freezing Spray Warning until noon CST Thursday for 
     LSZ150.

&&

$$

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