780
FXUS63 KDLH 190551
AFDDLH

Area Forecast Discussion
National Weather Service Duluth MN
1251 AM CDT Wed Mar 19 2025

.KEY MESSAGES...

- A round of accumulating snow expected late tonight through
  Wednesday, mainly in northwest Wisconsin. A Winter Storm
  Warning and Advisories are now in effect for parts of
  northwest Wisconsin.

- Glancing light precipitation chances (10-20%) on Friday, with
  more widespread precipitation chances (40-60%) on Sunday into
  early next week.

&&

.DISCUSSION...
Issued at 431 PM CDT Tue Mar 18 2025

This afternoon and evening we have had some mid level echoes on
radar, with a weak fgen band extending across the southern half
of the forecast area, generally from the Hinckley area east
through Hayward and Mellen. However, these radar echoes have
only been producing isolated surface reports of precipitation.
What we have had is a broad area of lower clouds over northwest
Wisconsin and west towards the Brainerd Lakes. This should
gradually weaken and be absorbed into the incoming spring storm
overnight.

Tonight through Wednesday night we have been focused on a
spring storm that moves across the region. The latest model runs
have pushed this system farther south than they were before,
which has really reduced the snowfall amounts. The latest
surface analysis puts the low developing over northeast CO as of
early this afternoon, which is showing signs of shifting east
into western Kansas. This low will push east and strengthen
tonight, moving across Kansas overnight and turning northeast to
move along the IA/MO border into northern IL Wednesday, and
then continuing northeast across Michigan Wednesday night. There
is a tight baroclinic zone ahead of this system which will
serve to focus the strong frontogenesis ahead of the surface
low, bringing a narrow band of heavy precipitation to southeast
Minnesota extending northeast across Wisconsin into the UP of
Michigan. Precipitation of the wintry mix type should push into
our southeastern CWA early Wednesday morning, then switch over
to all snow fairly quickly as the column becomes fully
saturated. While there is a low potential for a small amount of
sleet/freezing rain (10-15% chance) for early Wednesday morning,
these probabilities have been decreasing over the last few
runs. The track of this system has had a lot of spread with it,
along with a tight gradient in snowfall to the north of the band
of heaviest precipitation. With more and more high resolution
models in the mix with recent model runs, we have seen a
distinct southward shift in where the heaviest precipitation
will lay out on the ensembles, as well as a tightening of the
gradient on either side. A lot of the pros and cons that were
discussed early this morning remain in play. The time of day,
higher March sun angle, and near to above freezing temps are
against higher snowfall totals, while the deep forcing and
frontogenesis along with ample moisture remain supportive.
However, these more favorable factors are now shifting to just
southeast of the CWA as the system track shifts southeast, which
has caused our total snowfall to decrease for much of northwest
Wisconsin. However, southeastern Price county is likely to
continue to see at least a period of heavy snowfall in excess of
1" per hour during the afternoon hours. Snowfall should end
quickly during the evening from west to east as the deep forcing
and frontogenesis moves off to the east. We are now looking at
a shorter time range of just 12 hours from 12z to 00z of
potential for heavy precipitation.

Forecast snowfall amounts are now quite a bit lower for most of
northwest Wisconsin, but the tighter gradient means that
southern Price county still has warning criteria snowfall
amounts, with lighter amounts to the northwest, decreasing to an
inch or less from Ashland to Hayward. This kind of steep
gradient can make headline decisions hard, but given the spread
in the potential snowfall that still remains for northwest
Wisconsin, have decided to go with a Warning for Price county,
and Advisories for Sawyer, Ashland and Iron counties.

Thursday and Friday look like the warmest days of this
forecast, with the warmer temps across MN on Thursday, then
shifting to WI for Friday. The surface ridge axis over the
forecast area Thursday morning will gradually shift to east of
the area by evening, allowing a wedge of warm air to push in
from the west, and push high temperatures up into the 40s,
perhaps even low 50s on Friday. While this will feel warm, it is
still close to normal values for the date. Dry air moves in for
both days as well, with afternoon RH values dipping into the
20-30 percent range for portions of the area. A weak shortwave
with a surface cold front moving along the International Border
could bring some light rain/snow chances for Friday to northern
Minnesota, but doesn`t have a signal for being very significant.

Saturday night into Sunday night we have another spring system
which will move across the Northland Saturday night through
Monday, bringing a more widespread chance for precipitation.
Spread in ensemble members is still pretty large regarding the
timing, track, and intensity of this low pressure system, so a
bit too early to detail precipitation types or amounts.

&&

.AVIATION /06Z TAFS THROUGH 06Z THURSDAY/...
Issued at 1250 AM CDT Wed Mar 19 2025

Aside from some MVFR to near IFR stratus through much of the
overnight and morning at HYR and in north-central Wisconsin,
most of northeast Minnesota and northwest Wisconsin remains VFR
throughout the TAF period. Some snow does eventually move into
northwest Wisconsin later this morning through early evening,
though newer high resolution weather models have been shifting
the heavier snowband southeast, to the point that most of northwest
Wisconsin, including HYR, may largely miss out on snowfall
accumulations entirely. Have included some VCSH and PROB30
mentions at HYR for late morning through afternoon to account
for the lower-end snow potential, but could see this being
removed if the trend in snowfall forecasts continue moving
southeast.

Otherwise, expect northeast to north winds to increase on
Wednesday, with gusts approaching 20 to 30 knots for northwest
Wisconsin and areas along and south of HIB.

&&

.MARINE /FOR NEAR SHORE WATERS OF WESTERN LAKE SUPERIOR/...
Issued at 431 PM CDT Tue Mar 18 2025

Northeasterly winds to gradually increase through tonight into
Wednesday as a strong low pressure system passes southeast of
the region. Have issued Small Craft Advisories for the South
Shore and southwest arm of the Lake today into tonight for wind
gusts to 25 knots and elevated waves, and then for the remainder
of the nearshore waters on Wednesday for gusts to 25 to 30
knots. Wednesday there is a 20 to 40 percent chance of gale
force gusts for the Outer Apostle Islands east to Saxon Harbor.
For now have extended the Small Craft Advisories through
Wednesday night, but we will need to monitor for possible
upgrades in this area. Winds to gradually back into the
northwest Wednesday evening and diminish through Thursday.

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 7 AM this morning to 10 PM CDT
     this evening for WIZ003-004-008.
     Winter Storm Warning from 7 AM this morning to 10 PM CDT this
     evening for WIZ009.
MARINE...Small Craft Advisory until 4 AM CDT Thursday for LSZ121-
     142>148-150.
     Small Craft Advisory from 7 AM this morning to 4 AM CDT
     Thursday for LSZ140-141.

&&

$$

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