Lake Vermilion Area Weather – December 29-31

Tonight

Patchy fog before 11pm. Areas of freezing fog after 11pm. Otherwise, cloudy, with a low around 22. Calm wind.

Monday

Patchy fog between 9am and 11am. Widespread dense freezing fog before 9am. Otherwise, partly sunny, with a high near 28. Calm wind becoming northwest around 5 mph.

Monday Night

Mostly cloudy, with a low around 17. Northwest wind around 5 mph, with gusts as high as 15 mph.

Tuesday

Mostly cloudy, with a high near 22. Northwest wind 5 to 10 mph, with gusts as high as 20 mph.

Tuesday Night

Mostly cloudy, with a low around 10. West wind around 5 mph, with gusts as high as 15 mph.

New Year’s Day

Mostly cloudy, with a high near 15. West wind 5 to 10 mph, with gusts as high as 20 mph.

Wednesday Night

Mostly cloudy, with a low around 4. West wind around 5 mph, with gusts as high as 15 mph.

Thursday

Mostly cloudy, with a high near 11. West wind 5 to 10 mph, with gusts as high as 20 mph.

Thursday Night

Mostly cloudy, with a low around -2. Northwest wind around 5 mph, with gusts as high as 20 mph.

Friday

Mostly cloudy, with a high near 7. Northwest wind 5 to 10 mph, with gusts as high as 20 mph.

Friday Night

Mostly cloudy, with a low around -10. Northwest wind 5 to 10 mph, with gusts as high as 20 mph.

Saturday

Mostly sunny and cold, with a high near 4. Northwest wind around 5 mph, with gusts as high as 15 mph.

Saturday Night

Mostly cloudy, with a low around -10. Northwest wind around 5 mph becoming calm.

Sunday

Mostly cloudy, with a high near 6. North wind around 5 mph.

KEY MESSAGES

– Areas of dense fog this afternoon will become widespread tonight with visibility to a quarter mile or less at times for the Monday morning commute and temperatures below freezing, causing some roads, sidewalks, and other surfaces to become icy.
– Colder to ring in the new year with temperatures falling through the week. Wind chills as cold as 20 to 30 below zero Friday night.
– Light lake effect snow showers for parts of the south shore mid-to-late week, with a total of 1 to 4 inches of snow most likely (80% chance within this range) for parts of northern Ashland and Iron counties in northwest Wisconsin. Otherwise no measurable precipitation through the week and just a low potential for light snowfall next weekend – the probability of greater an inch of snow is less than 30 percent for the Northland next weekend.

DISCUSSION

Issued at 1258 PM CST Sun Dec 29 2024

A seasonable and fairly benign pattern this week to ring in the new
year. On the synoptic scale a broad upper low over Hudson Bay and
northern Ontario gradually deepens amidst an otherwise unimpeded
zonal flow pattern across the CONUS. This deepening upper low and
then a ridge building over the Rockies late in the week will result
in cold air from Canada infiltrating the Northern Plains and Upper
Midwest through the week, with 850mb temps as cold as -15C to -20C
over the Northland by late-week. The upstream airmass is largely
saturated at mid to low levels, which means clouds are expected to
stick around through most of the week.

This northwest flow pattern will be favorable for lake effect snow
showers along parts of the south shore. While the low level wind
direction is more west-northwesterly than would be ideally for lake
effect in northwest Wisconsin, the combination of saturated low
levels and persistence and relatively light speed of the low level
winds leans towards a higher likelihood of lake effect snow showers
for the south shore, with the Bayfield Peninsula and northern parts
of Ashland and Iron counties expected to see some light snow showers
by mid to late week. Amounts will not be particularly higher, but
around 1 to 4 inches over the course of the mid to late week
timeframe seems reasonable.

As the upper low spins to the north, there will be a few very weak
mid-level shortwave troughs embedded in the flow. Given the
saturated low levels, some weak lift from these impulses may lead to
light snow showers in northern Minnesota Tuesday, Wednesday, and
Thursday. Measurable accumulations are not expected, but and off and
on flurry and coating of snow is at least possible for a few spots
in northern Minnesota around mid-week.

By the end of the week high temperatures will be in the single
digits with lows near to below zero Thursday night and Friday night.
The combination of cold air and light northwest winds could lead to
wind chill values at least approaching 20 to 30 below zero Thursday
night, Friday, and Friday night.

Next weekend a ridge builds over the Rockies and into the Great
Plains ahead of a mid-level trough that moves into the Pacific
Northwest. This trough will eventually move into the Great Plains
over the weekend, but guidance has trended south with the location
of the surface low and associated sensible weather impacts. Despite
some spread in the model guidance, impacts to the Northland appear
minimal at worst, with the most likely scenario being the bulk of
the precipitation remaining south of our region.

AVIATION

Issued at 535 PM CST Sun Dec 29 2024

Widespread IFR to LIFR to continue to deteriorate this evening,
with a period of LIFR ceilings and VLIFR visibilities expected
overnight tonight for all terminals. A very slow improvement can
be expected to begin around mid morning, continuing through much
of the afternoon, with most sites expected to get to MVFR
ceilings and MVFR or even VFR visibilities by 20z. Conditions
are expected to begin to deteriorate once again around 00z, with
timing somewhat uncertain for now.

MARINE /FOR NEAR SHORE WATERS OF WESTERN LAKE SUPERIOR

Issued at 1258 PM CST Sun Dec 29 2024

Dense fog may reduce visibility near the head of the lake, with
visibilities to a mile or less from Two Harbors to the Twin Ports,
and at least patchy fog along the south shore. This fog will be on
and off today, but then redevelop this evening and persist again on
Monday morning. Otherwise near calm winds today/tonight becoming
northwesterly on Monday.

Persistent northwesterly winds of 10 to 15 knots with gusts to 20-25
knots through much of the work week will leading to building waves
along parts of the south shore Wednesday, Thursday, and Friday. Wave
heights of 2 to 4 feet from Superior to Port Wing to the Apostle
Islands may be hazardous to small craft, with at least a Small Craft
Advisory expected for the outer Apostle Islands zone Thursday into
Friday.

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