506
FXUS63 KDLH 040608
AFDDLH

Area Forecast Discussion
National Weather Service Duluth MN
1208 AM CST Thu Dec 4 2025

.KEY MESSAGES...

- Cooling temperatures throughout today will lead to much below
  normal lows tonight and cold wind chills. Temperatures will
  continue to oscillate throughout the week.

- Another fast moving clipper will move through the Northland
  tomorrow. Several hours of moderate to heavy snowfall rates
  are possible in the Iron Range and Arrowhead.

- There will be several more chances for snowfall this weekend
  into next week.

&&

.DISCUSSION...
Issued at 110 PM CST Wed Dec 3 2025

A cold air mass behind a high pressure system continues to
shift south, chasing away the flurries that occurred this
morning. There remains a few streams of clouds along the
Borderlands downwind of large inland lakes in Canada, which
could continue to produce scattered flurries for the next few
hours, but the air is so dry that hardly any snow is expected to
reach the ground. This dry air is also beginning to reach Iron
County, where lake effect snow is rapidly dissipating as well.

Temperatures continue to plummet under this cold air mass, and
is expected to reach its minimum tonight. Low temperatures in
the negative single digits and teens are expected tonight across
the Northland, accompanied with winds still in the 10-15 mph
range, will produce wind chills ranging from -15 to -25
degrees. Thursday won`t be quite as cold, as the coldest part of
the air mass moves off to the east, but high temperatures are
still only expected to be in the teens.

Also expected tomorrow, another Alberta clipper will quickly
move along the Northern Plains and through the Northland
Thursday late afternoon and overnight. It is a surprisingly
potent little thing, with plenty of upper level forcing and
efficient frontogenesis. There`s a little to be desired with
lapse rates, which range around 6-7 C/km, but is sufficient
enough. So, portions of the Iron Range, Borderlands, and
Arrowhead could see some moderate snowfall in a short amount of
time. Snowfall rates 0.5-0.75"/hour are possible at times. Since
the snow will be brief, only up to 3 inches are expected, but
the Arrowhead may see higher snowfall totals. The reason being,
once flow switches to the southwest tomorrow ahead of the
system, CAMS show a thin band of convergence ahead of the warm
air advection that will produce snowfall over Lake Superior
initially. As that band continues to move north, it will snow
onto the Arrowhead, providing another up to 2 inches in addition
to the snowfall with the clipper. Like today, lingering chances
for flurries and light lake effect snow in Iron County are
likely with cold air advection behind the system Friday.

Rinse and repeat today`s temperature forecast for Saturday into
Sunday, where a cold air mass will cause temperatures to decrease
throughout the day and reach their minimum overnight.
Temperatures will also be similar, in the negative single digits
to low teens. However, winds will not be as strong that night,
so wind chills will largely be in the same range as the
temperatures.

Global models are in good agreement for a larger clipper moving
through the area early next week, and also looks like it could
bring widespread snowfall to our CWA. This will likely be our
next system to watch through the weekend.

&&

.AVIATION /06Z TAFS THROUGH 06Z FRIDAY/...
Issued at 1208 AM CST Thu Dec 4 2025

VFR conditions prevail across the Northland early this morning
with clear skies over most of the region. Clouds will increase
around daybreak as a clipper system approaches the area. Any
MVFR conditions will likely hold off until late afternoon or
into the evening Thursday. Snow from this system will mainly
affect northern areas with INL being the most likely. Snow may
be heavier at times with IFR or lower VSBYs possible for a time.
Snow may reach as far south as HIB, but confidence on this is
too low to include more that PROB30s at this time. Winds will be
southerly through the day with gusts to 20 to 25 knots before
turning westerly late. A low level jet will move into the region
later this afternoon and evening bringing a period of LLWS to
the terminals.

&&

.MARINE /FOR NEAR SHORE WATERS OF WESTERN LAKE SUPERIOR/...
Issued at 110 PM CST Wed Dec 3 2025

As a high pressure passes to the south, winds will shift from
the northwest to the southwest tonight into Thursday. Winds
will remain elevated through tonight, still a hazard to small
craft. Winds will decrease in the early morning, but will
quickly increase once again out of the southwest. There is a
70-90% chance for gales across western Lake Superior,
particularly along the North Shore and around the Apostle
Islands. Small Craft Advisories and Gale Watches are in effect
into early Friday.

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

&&

.DLH WATCHES/WARNINGS/ADVISORIES...
MN...None.
WI...None.
MARINE...Small Craft Advisory until 10 AM CST Friday for LSZ121-145>148.
     Small Craft Advisory until noon CST Thursday for LSZ140>144-
     150.
     Gale Watch from Thursday afternoon through Thursday evening
     for LSZ140>144-150.

&&

$$

DISCUSSION...KML
AVIATION...BJH
MARINE...KML