487
FXUS63 KDLH 222059
AFDDLH

Area Forecast Discussion
National Weather Service Duluth MN
259 PM CST Wed Jan 22 2025

.KEY MESSAGES...

- Wind chills down to around -30 tonight for parts of northeast
  Minnesota.

- Warmer weather is expected Friday into Saturday along with
  some light snow possible (30% chance).

- Light snow and warm temperatures continue into next week. Snow
  accumulations are expected to be light.

&&

.DISCUSSION...
Issued at 254 PM CST Wed Jan 22 2025

A cold front is passing through northwest Wisconsin this
afternoon and producing an organized line of snow as it makes
its way southeast. We have had to periodically issue Snow Squall
Warnings as visibilities have been observed at 1/2 mile and we
suspect visibilities are lower in spots. This threat will
persist through mid-afternoon as the front continues southeast.

Behind the front, breezy northwest winds with cold air advection
are producing the usual horizontal convective rolls with some
embedded flurries and light snow showers. Kept PoPs in the
10-20% range through the evening for most places, dropping them
off gradually from northwest to southeast as dry air invades.

We can expect some chilly temperatures tonight with lows falling
into the teens below zero across the Canadian Border and into
the Arrowhead. We issued a few Cold Weather Advisories where
confidence is highest that we may see wind chills down to around
-30. We may need to expand these headlines to a few more
 counties if winds end up being a little higher than currently
 forecast, but we will continue to monitor for that potential.

Along the South Shore, expect the lake-effect snow machine to
get going tonight with 850-mb temps falling to around -20 to
-22. This will be easily favorable for LES bands, but we do have
 a dry air mass working against producing significant
 accumulations. Snow amounts have gone down a bit since the last
 update, and snowfall rates are not currently expected to be
 significant enough to warrant any advisories. With that said,
 several inches of snow (up to around 3-6") is expected in
 northern Iron county from tonight through Thursday. It`s just
 expected to come in brief bouts of moderate to heavier snow
 showers, and should start to taper off Thursday afternoon as
 winds become more westerly.

Southerly flow develops again going into Friday. Flow aloft is
expected to be predominantly west to northwesterly with a train
of clipper systems passing over or near the Northland, bringing
periodic light snow episodes along with warming temperatures.
The first clipper will pass through Friday into Saturday, and
without a great moisture source, we can expect light amounts.
Models are currently in pretty good agreement right now, and
there aren`t any outliers suggesting any anomalously heavier
snow. Another clipper may pass through around Monday, but models
are not in perfect agreement on the track of this one.

&&

.AVIATION /18Z TAFS THROUGH 18Z THURSDAY/...
Issued at 1157 AM CST Wed Jan 22 2025

A cold front swinging through will continue to cause winds to
become northwesterly, and will remain breezy through the
afternoon and evening before lightening up somewhat. Snow
showers along the cold front may affect HYR with some MVFR
visibilities in the next hour or so. Otherwise, expect a mix of
MVFR and VFR ceilings through the afternoon as drier air moves
in from the northwest. This will clear out a lot of clouds, but
then we get into a well-mixed lower atmosphere that will keep
areas of broken stratocumulus around as well, so this leads to
low confidence in timing of when ceilings will be MVFR versus
VFR, but expect them to bounce back and forth through the
afternoon and evening. Skies are largely expected to scatter out
tonight, leading to predominantly VFR ceilings through the
period.

&&

.MARINE /FOR NEAR SHORE WATERS OF WESTERN LAKE SUPERIOR/...
Issued at 254 PM CST Wed Jan 22 2025

Breezy northwest winds continue through Thursday morning. Gusts
from 20-30 kt expected pretty much everywhere tonight, then
lingering a few hours past sunrise along the Outer Apostle
Islands and areas along the North Shore. Expanded the Small
Craft Advisory along the North Shore a few hours past sunrise as
katabatic downsloping winds may keep gusts in the 20-25 kt range
a while longer there. Winds gradually decrease a bit Thursday
afternoon, then become southwesterly going into Friday. Winds
gusting 20-30 kt are possible around Grand Marais to Grand
Portage along with wave heights approaching 6-7 ft. Gusty winds
are possible in the Outer Apostle Islands as well. Small Craft
Advisories may be needed.

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 from 3 AM to 9 AM CST Thursday for
     MNZ010-012-021.
WI...None.
MARINE...Small Craft Advisory until 9 AM CST Thursday for LSZ140>142-
     150.
     Small Craft Advisory until 4 AM CST Thursday for LSZ143>148.

&&

$$

DISCUSSION...JDS
AVIATION...JDS
MARINE...JDS