textproduct: Duluth

KEY MESSAGES

- Patchy freezing fog and rime ice on the North Shore into tonight.

- Light snow accumulations up to one inch along the Canadian border tonight.

- Gusty northwest winds on Tuesday.

- Messy winter storm with mixed precipitation possible for Christmas and Friday, with the potential for travel impacts.

DISCUSSION

Issued at 223 PM CST Mon Dec 22 2025

Moisture advection off Lake Superior continues to create areas of freezing fog and rime ice on trees and elevated surfaces along the higher terrain of the North Shore. Webcams indicate lowered visibilities in the Sawtooth Mountains, and these conditions are expected to persist through the evening. A shift in the wind direction tonight will eventually help clear these obstructions as a clipper system moves across the region from the west.

This clipper system has trended slightly further north in recent model runs, meaning the bulk of the accumulating snow will be confined to areas right along the Canadian border. Total snow accumulations through Tuesday morning are expected to be between one quarter of an inch and one inch for the Borderlands. While some high-resolution models have hinted at a window for mixed precipitation or freezing drizzle, the probability has dropped significantly, and the forecast currently favors primarily light snow for the northernmost counties.

Behind the departing clipper, a tighter pressure gradient will develop on Tuesday morning, leading to a period of brisk northwest winds. Gusts between 25 and 35 mph are possible, particularly along the North Shore where downslope enhancement can occur. A warming trend then takes hold for Wednesday and Thursday as an upper-level ridge builds over the central United States. Afternoon high temperatures will likely reach the mid- twenties to low thirties across much of the Northland. A weak disturbance may pass through on Wednesday morning, though most precipitation is currently projected to fall over the open waters of Lake Superior and toward the Upper Peninsula of Michigan.

Attention remains focused on a potentially impactful and messy weather system arriving late on Christmas Day and continuing through Friday. A push of warm air aloft will likely create a melting layer, introducing the threat of multiple precipitation types including rain, freezing rain, and heavy wet snow. Significant uncertainty remains regarding the exact track of this system, which will dictate where the heaviest accumulations and most dangerous ice potential occur. Despite PWATs projected to be in the 99th percentile, current indications suggest that while snow amounts may be light for much of the region. The Arrowhead, however, could see higher totals due to terrain and lake enhancement. Another clipper system may follow closely behind this storm for the weekend, potentially bringing additional mixed precipitation to the Northland. Uncertainty in this system is very high and will depend on how the Christmas system develops. Global models show the following system also not having a lot of moisture, which will limit accumulations.

AVIATION /00Z TAFS THROUGH 00Z TUESDAY/

Issued at 525 PM CST Mon Dec 22 2025

Seeing mainly VFR cloud bases early this evening, with the exception being some BKN IFR ceilings with onshore flow at DLH and some fog/low ceilings along the North Shore. Light snow showers are expected across far northern Minnesota later this evening into part of the overnight hours. Have mention of the best timing potential for this light snow in the INL TAF. Expect accumulations to be less than one inch. There is a 20% chance to see some stray snow at HIB, but potential was too low to include in the TAF. Expect IFR ceilings to arrive behind the snow tonight into early Tuesday morning for INL and HIB, though IFR ceilings could briefly reach DLH and HYR Tuesday morning, as well. Widespread MVFR elsewhere, with ceilings gradually improving and scattering out to VFR towards midday and afternoon Tuesday.

Lighter ESE winds this evening veer to westerly tonight and northwesterly on Tuesday while increasing with gusts of 15-25 kt for most later tonight into Tuesday along with the veering winds. DLH gusts could push towards 30 kt, with gusts to around 35 kt along the North Shore daytime Tuesday.

MARINE

Issued at 223 PM CST Mon Dec 22 2025

An easterly wind of 10 to 15 knots will persist through this evening with waves of 1 to 2 feet. Winds will turn southwest after midnight and then northwest by Tuesday morning. Strong northwest winds are expected Tuesday with gusts up to 30 knots, and potentially up to 35 knots near Grand Marais. Small Craft Advisories are in effect for all nearshore zones. Waves will build to 3 to 6 feet in the Apostle Islands on Tuesday before subsiding Tuesday 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...None. MARINE...Small Craft Advisory from 6 AM to 4 PM CST Tuesday for LSZ121- 140>148-150.