561
FXUS63 KDLH 191128
AFDDLH

Area Forecast Discussion
National Weather Service Duluth MN
628 AM CDT Wed Mar 19 2025

.KEY MESSAGES...

- Accumulating snow expected in north-central Wisconsin today,
  though the higher snowfall amounts have shifted southeast of
  the Northland. A Winter Weather Advisory is in effect late
  this morning through mid-evening for Price County.

- Glancing light rain/snow chances (10-20%) on Friday, with more
  widespread precipitation chances (40-70%) for Saturday night
  into Monday.

&&

.DISCUSSION...
Issued at 357 AM CDT Wed Mar 19 2025

Today`s Winter System:

Deep low pressure over Kansas early this morning will continue
tracking northeast across the Iowa/Missouri border by midday,
northern Illinois/southern Lake Michigan this evening, and into
the lower Michigan Peninsula tonight. The low pressure`s track
has shifted slightly farther southeasterly, there has been a
trend in hi-res and global ensemble model guidance of the
higher snowfall amounts sliding primarily southeast of the
Northland, leading to a reduction in forecast snowfall amounts
yet again with this forecast update. Additionally, the
deformation band axis/deeper synoptic lift for the heavier snow
has also shifted slightly southeast, with a sharp gradient in
snowfall amounts expected on it`s northwest side into portions
of north-central Wisconsin. The axis of heaviest snowfall (6"+)
is now forecast to extend from north-central Iowa to far
southeast Minnesota, central to northeast Wisconsin, and into
the U.P.

As for timing, some radar echoes are already present in
northwest Wisconsin early this morning, but substantial dry air
in the low-levels should prevent precipitation from reaching the
ground until mid to late morning when the better forcing for
ascent and moistening of the atmospheric column occur. Forecast
thermal profiles favor precipitation remaining largely as snow
throughout the day today despite high temperatures in northwest
Wisconsin warming above freezing into the mid to upper 30s.
The bulk of the snow is forecast to fall during the afternoon
when lift/forcing is the strongest. However, most of the
thermal profile aloft being warmer than the dendritic growth
zone should lead to some riming of snow crystals and the higher
sun angle this time of year combined with snow falling during
the day should knock down snow-to-liquid ratios a bit, leading
to a wetter snow and also lead to lower snow totals. Even so,
the latest 00Z HREF guidance still suggests southeastern
portions of Price County closer to the deformation band could
see snow rates briefly approach 0.5-0.75"/hr for a few hours
this afternoon. Snow rates quickly decrease and snow exits to
the east of north-central Wisconsin by mid to late evening.

As for amounts, expect the highest totals in our area to be in
Price County generally in the range of 1-4", with the higher of
these totals in southeastern portions of the county. An inch or
less is forecast for Sawyer, Ashland, and Iron counties, with
little to no accumulations for the remainder of northwest
Wisconsin and no accumulations in east-central or northeast
Minnesota. Strong northerly winds with gusts of 25 to 35 mph are
forecast for today, so areas in Price County that do see a
couple inches of snow accumulations today could get some patchy
blowing snow and reduced visibility this afternoon into early
this evening. Given the shift to lower snowfall amounts, the
previous Winter Weather Advisories for Sawyer, Ashland, and Iron
counties have been cancelled, with only a Winter Weather
Advisory remaining for Price County from late this morning into
this evening.

Thursday - Saturday:

Conditions warm above average for most of the Northland for
Thursday and Friday behind the departing low pressure system,
with highs in the upper 30s to 40s on Thursday and 40s to around
50 degrees for all but north-central Minnesota where highs will
be in the 30s. A drier airmass on Thursday will also likely lead
to afternoon relative humidities in the 20s to mid 30s (%) range,
but winds shouldn`t be overly gusty. Low pressure and an
associated cold front will be sliding southeast across the
Northland on Friday, with some along- and post- frontal light
snow/rain showers possible (10-20% chance), but precipitation
amounts look light with minimal to no impacts.

Temperatures cool off back into the teens to single digits above
zero Friday night behind Friday`s cold front, and then warm into
the upper 20s to 30s for Saturday, coldest in far northern
Minnesota. Expect an even drier airmass on Saturday relative to
Thursday, though winds will again not be too gusty. Afternoon
relative humidities could dip into the teens to mid 20s for
Saturday afternoon, so that will be a timeframe to look at
possible fire weather concerns depending on how winds trend.

Saturday Night - Early Next Week:

For Saturday night into portions of Monday, global ensembles and
cluster guidance point to a more robust Clipper system diving
southeast across the Upper Midwest, bringing better chances
(40-70%) for more widespread precipitation. There is still
remains a fairly large amount of spread in the tack of this low
pressure system, which will play a factor in both temperatures
and precipitation types (predominantly snow vs. rain/snow mix) as
the system moves through. With these uncertainties in mind, NBM
probabilities are 30-60% for >2" of snow and 20-50% for >4" of
snow, with the highest of these probabilities along the North
Shore due to expected onshore flow of winds off of Lake Superior
with east to northeast winds.

Additional shortwave energy in northwest flow aloft could bring
additional precipitation for early to mid-next week, but
confidence in timing, placement, and amounts remains low at this
time.

&&

.AVIATION /12Z TAFS THROUGH 12Z THURSDAY/...
Issued at 628 AM CDT Wed Mar 19 2025

No significant changes to the TAFs with this update. Aside from
some MVFR stratus through much of the morning at HYR/northwest
Wisconsin, most of northeast Minnesota and northwest Wisconsin
remains VFR throughout the TAF period. Snow eventually moves
into northwest Wisconsin later this morning until mid evening,
with the heaviest snow band remaining southeast of PBH. Have
kept some VCSH and PROB30 mentions at HYR for the afternoon to
account for the lower-end snow potential, but accumulations from
snowfall look minimal.

Otherwise, expect northeast to north winds to increase on
today, with gusts approaching 20 to 30 knots, highest for BRD
east into northwest Wisconsin. Wind gusts back to northwesterly
and decrease late in the TAF period.

&&

.MARINE /FOR NEAR SHORE WATERS OF WESTERN LAKE SUPERIOR/...
Issued at 357 AM CDT Wed Mar 19 2025

Northeast to northerly winds to gradually increase today as a
strong low pressure system passes southeast of the region. Small
Craft Advisories remain in effect for the South Shore and
southwest arm of the Lake today through early this morning for
wind gusts to 25 knots and elevated waves, and then for all of
the nearshore waters today into early Thursday morning for gusts
of 25 to 30 knots. While winds briefly weaken as they back to
westerly Thursday morning, they increase again out of the
southwest Thursday afternoon into Friday morning, leading to
additional hazardous conditions for smaller vessels. A cold
front then passes through on daytime Friday, with winds
increasing out of the northwest behind the front again for
Friday afternoon into Friday night.

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

&&

.DLH WATCHES/WARNINGS/ADVISORIES...
MN...None.
WI...Winter Weather Advisory from 10 AM this morning to 10 PM CDT
     this evening for WIZ009.
MARINE...Small Craft Advisory until 7 AM CDT Thursday for LSZ121-
     142>148-150.
     Small Craft Advisory until 7 AM CDT Thursday for LSZ140-141.

&&

$$

DISCUSSION...Rothstein
AVIATION...Rothstein
MARINE...Rothstein