textproduct: Duluth

KEY MESSAGES

- Cooling temperatures throughout today will lead to much below normal lows tonight and cold wind chills. Temperatures will continue to oscillate throughout the week.

- Another fast moving clipper will move through the Northland tomorrow. Several hours of moderate to heavy snowfall rates are possible in the Iron Range and Arrowhead.

- There will be several more chances for snowfall this weekend into next week.

DISCUSSION

Issued at 110 PM CST Wed Dec 3 2025

A cold air mass behind a high pressure system continues to shift south, chasing away the flurries that occurred this morning. There remains a few streams of clouds along the Borderlands downwind of large inland lakes in Canada, which could continue to produce scattered flurries for the next few hours, but the air is so dry that hardly any snow is expected to reach the ground. This dry air is also beginning to reach Iron County, where lake effect snow is rapidly dissipating as well.

Temperatures continue to plummet under this cold air mass, and is expected to reach its minimum tonight. Low temperatures in the negative single digits and teens are expected tonight across the Northland, accompanied with winds still in the 10-15 mph range, will produce wind chills ranging from -15 to -25 degrees. Thursday won't be quite as cold, as the coldest part of the air mass moves off to the east, but high temperatures are still only expected to be in the teens.

Also expected tomorrow, another Alberta clipper will quickly move along the Northern Plains and through the Northland Thursday late afternoon and overnight. It is a surprisingly potent little thing, with plenty of upper level forcing and efficient frontogenesis. There's a little to be desired with lapse rates, which range around 6-7 C/km, but is sufficient enough. So, portions of the Iron Range, Borderlands, and Arrowhead could see some moderate snowfall in a short amount of time. Snowfall rates 0.5-0.75"/hour are possible at times. Since the snow will be brief, only up to 3 inches are expected, but the Arrowhead may see higher snowfall totals. The reason being, once flow switches to the southwest tomorrow ahead of the system, CAMS show a thin band of convergence ahead of the warm air advection that will produce snowfall over Lake Superior initially. As that band continues to move north, it will snow onto the Arrowhead, providing another up to 2 inches in addition to the snowfall with the clipper. Like today, lingering chances for flurries and light lake effect snow in Iron County are likely with cold air advection behind the system Friday.

Rinse and repeat today's temperature forecast for Saturday into Sunday, where a cold air mass will cause temperatures to decrease throughout the day and reach their minimum overnight. Temperatures will also be similar, in the negative single digits to low teens. However, winds will not be as strong that night, so wind chills will largely be in the same range as the temperatures.

Global models are in good agreement for a larger clipper moving through the area early next week, and also looks like it could bring widespread snowfall to our CWA. This will likely be our next system to watch through the weekend.

AVIATION /06Z TAFS THROUGH 06Z FRIDAY/

Issued at 1208 AM CST Thu Dec 4 2025

VFR conditions prevail across the Northland early this morning with clear skies over most of the region. Clouds will increase around daybreak as a clipper system approaches the area. Any MVFR conditions will likely hold off until late afternoon or into the evening Thursday. Snow from this system will mainly affect northern areas with INL being the most likely. Snow may be heavier at times with IFR or lower VSBYs possible for a time. Snow may reach as far south as HIB, but confidence on this is too low to include more that PROB30s at this time. Winds will be southerly through the day with gusts to 20 to 25 knots before turning westerly late. A low level jet will move into the region later this afternoon and evening bringing a period of LLWS to the terminals.

MARINE /FOR NEAR SHORE WATERS OF WESTERN LAKE SUPERIOR/

Issued at 110 PM CST Wed Dec 3 2025

As a high pressure passes to the south, winds will shift from the northwest to the southwest tonight into Thursday. Winds will remain elevated through tonight, still a hazard to small craft. Winds will decrease in the early morning, but will quickly increase once again out of the southwest. There is a 70-90% chance for gales across western Lake Superior, particularly along the North Shore and around the Apostle Islands. Small Craft Advisories and Gale Watches are in effect into early Friday.

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

DLH WATCHES/WARNINGS/ADVISORIES

MN...None. WI...None. MARINE...Small Craft Advisory until 10 AM CST Friday for LSZ121-145>148. Small Craft Advisory until noon CST Thursday for LSZ140>144- 150. Gale Watch from Thursday afternoon through Thursday evening for LSZ140>144-150.