Lake Vermilion Area Weather – March 2-4

KEY MESSAGES

*  Warm temperatures are expected on Monday with highs in the 40s and 50s.
*  A messy storm will bring some mixed precipitation on Tuesday, leading into accumulating snow and blowing snow (especially in northwest Wisconsin) Tuesday night into Wednesday.
*  Quieter and more seasonable weather through the rest of the week, then perhaps warming up again this weekend.

DISCUSSION

Issued at 213 PM CST Sun Mar 2 2025

This Afternoon through Monday:

It`s a pretty quiet afternoon out there with mixed clouds and sun.
Warm air advection and ridging aloft have allowed for temperatures
to rise above freezing for much of the region. We will fall below
freezing tonight, and while winds will be light and skies mostly
clear, the presence of a dry air mass will likely make fog chances
pretty minimal despite a bit of added low-level moisture from melted
snow.

We`re still looking at some pretty toasty temperatures on Monday
with the ridge axis overhead. Still leaning on the higher end of
guidance, favoring highs in the 40s and low 50s. From a pattern
recognition standpoint, these early spring warm days often tend to
overachieve in high temperatures with low dew points expected.

Monday night through Wednesday (messy late-winter / early-spring
storm):

We continue to watch a deep trough moving in over the intermountain
west, which is expected to become negatively tilted and deepening a
surface low that will track northeast through the central Great
Lakes region. We will be on the northwest edge of impacts from this
system, and as such, there`s quite a bit of spread in the models as
far as QPF goes. While the long-range models have been in relatively
good agreement with the approximate track of the low, the fact that
we are on the northwest side and expecting a southeast-to-northwest
gradient in QPF means that slight shifts in the storm track can mean
notable differences in impacts for the region.

As we go into Monday night, a surface and near-surface inverted
trough associated with a warm front and warm air advection is
expected to develop over the northern Plains. The first rounds of
mixed precipitation are expected to develop in association with
this. Basically anywhere roughly from US-2 and south is expected to
be primarily rain with plenty of warm air in place. Temperatures may
hug freezing in places like the Twin Ports, but after a warm Monday,
freezing rain should be isolated there. Around the Iron Range and
points north, though, a period of light freezing rain and perhaps
snow is possible as the fgen band drifts to the north and
temperatures are cooler. A several hour period of light freezing
rain early Tuesday morning may produce a glaze to perhaps a few
hundredths of an inch of ice, and may create some impacts for the
Tuesday morning commute. Around mid-Tuesday morning to mid-day,
there are some hints that the fgen band may combine with just enough
mid-level cooling and adiabatic cooling to produce a narrow band of
some moderate snow somewhere around the Iron Range. If this happens,
there should be plenty of riming as the low-levels remain just below
freezing to around freezing. Nevertheless, snowfall rates could
briefly increase for a few hours and produce around an inch or so of
wet snow for some places. The combination of the light freezing rain
and localized fgen snow potential may be enough to warrant some
Winter Weather Advisories Tuesday morning through mid-day.

Tuesday afternoon, the fgen band over northeast Minnesota will
likely start to weaken, with all precipitation transitioning over to
light rain for the afternoon across the region as temperatures warm
above freezing.

The next and likely more impactful round of precipitation will
arrive Tuesday night as the surface low passes by to the southeast.
Broad synoptic lift and fgen on the northwest side of the low is
expected to bring a swath of moderate to heavy precipitation. With
colder air starting to filter in, we can expect a transition over to
snowfall Tuesday night, with moderate to heavy snow falling through
Wednesday morning and tapering off in the afternoon. With that said,
I mentioned above that we will be on the far northwest side of this
storm, and we can expect a somewhat tight QPF gradient. Northwest
Wisconsin remains under the greatest threat for seeing heavy snow
Tuesday night into Wednesday. With this update, confidence is still
not high enough to hoist a formal Winter Storm Watch because minor
storm track differences can make quite a difference. In addition,
there is some question on how fast the lower atmosphere can cool
once rain transitions to snow, and if this happens slower, more
riming and thus lower snowfall amounts may occur. While a watch is
not issued with this update, the areas we currently have the highest
confidence for higher amounts (e.g. 6″+) are Bayfield, Ashland, and
Iron counties, where northeasterly winds may orographically enhance
the snow there. There is some question about how much lake
enhancement we may get, but currently it seems like it will be too
warm for very much lake enhancement. This looks to be primarily a
meso/synoptic driven storm with a pinch of orographic enhancement.
Areas like eastern Douglas county, then further south into
Sawyer/Price counties could see some higher amounts as well, but it
depends on the storm track and how far northwest the moisture and
fgen make it. Once we get a bit more confidence on where the main
axis of snow is likely to set up, we will likely issue some Winter
Storm Watches.

In addition to the snow, a tight pressure gradient will lead to
gusty winds gusting to around 30-35 mph, and possibly locally as
high as 40 mph along the immediate South Shore with onshore flow.
This combined with the blowing snow could lead to some near-whiteout
conditions at times. The consistency of the snow is expected to be
heavy and wet for most of Tuesday night, then become a bit fluffier
as colder air works its way in on Wednesday. Due to the initially
wet consistency, blizzard conditions are not expected except perhaps
locally and briefly. Snow ends from west to east Wednesday afternoon.

Wednesday night through next weekend:

Cold air advection will mean some relatively cooler temperatures to
end the week along with fairly quiet weather. We will likely remain
in a day thaw / night freeze cycle, which could lead to slippery
sidewalks and decks. A somewhat potent low is looking like it will
pass well to our south going into Friday, so we remain in a quiet
weather pattern with only stray flurry chances going into the
weekend. There are some hints at perhaps a small clipper system over
the weekend, then a broader ridging pattern going into early next
week which could bring warmer weather.

AVIATION