textproduct: Duluth

KEY MESSAGES

- Slight chance of some light snow or flurries late tonight and Wednesday morning, mainly across the Arrowhead.

- A larger, messy system could affect the area Dec 25-26. There is the potential for rain, freezing rain, and heavy wet snow which could affect holiday travel. The best chance for snow accumulations of several inches or more is over the MN Arrowhead, highest in Cook County. Locations south of US-2 could see a light glaze of ice accumulation.

- A second system could follow the first for the weekend with another chance for mixed precipitation and strong winds.

- Above normal temperatures are expected through Saturday, with Friday and Saturday being the warmest of the 7 day period with widespread highs near or above freezing. Below normal temperatures return Sunday - Monday.

DISCUSSION

Issued at 156 PM CST Tue Dec 23 2025

The story through much of this week will be the broad, flat ridging over much of the CONUS and troughing along the West Coast, with weak shortwaves riding over the ridge, bringing waves of Pacific moisture eastward. The first of these will arrive tonight.

But first, surface high pressure will quickly slide across the Upper Midwest this afternoon and tonight, with winds diminishing this evening. Temperatures will fall early, reaching lows in the single digits and teens before or around midnight. Winds swing around to the south as the surface high quickly exits to the east. This allows for weak warm advection, with temperatures warming through the overnight hours, and isentropic lift as a weak shortwave rides over the ridge. This shortwave brings a wave of Pacific moisture, but the deepest moisture remains well to our north along with better forcing. Over the Northland, a substantial dry layer and limited surface moisture will limit precipitation. There is weak lift over the Arrowhead, and weak and brief onshore flow that could help enhance some light snow Wednesday morning. CAMs continue to force out spotty precipitation, while global models are much more stingy. Will carry low pops and a trace of snow for parts of the Arrowhead, but do not expect impacts. Behind this wave, a broad surface high will slide from central Manitoba toward southern Ontario.

Attention turns to the Christmas Day system, with a weak low coming out of the northern Rockies and sliding southeastward toward the central Mississippi River Valley. Ahead of a stronger shortwave riding through the ridge, southerly flow sets up warm advection west of the surface high now centered north of Lake Superior in southwest Ontario. With only a weak surface low, and it being rather removed from the Northland, forcing will be driven by the shortwave aloft and isentropic lift. This system brings a larger wave of Pacific moisture, and combined with a 40-50kt low level jet, most of the area should see measurable precipitation. North of the Iron Range will see light snow moving in during the afternoon. There will be some dry air to overcome, and precipitation will likely hold off until early evening near and south of a line from Brainerd to Duluth. Precipitation will start out as mostly snow, but with the strong LLJ and warm nose, a transition to a wintry mix is expected Thursday night, especially south of US-2. There could be additional enhancement along the North Shore with strong south to southeast winds Thursday night. Best snow accumulations will be in Arrowhead, especially Cook County, where up to 6 inches is possible. Further south, snow accumulations will be limited, and given the transition to freezing rain, a light glaze of ice is possible south of the Iron Range and across northwest Wisconsin. We are still 48+hrs from impactful precipitation, and some uncertainty on how much moisture is available. Will hold off on any headline decisions today.

A surface high quickly passes by Friday, with weak southerly flow returning Friday night. The board flat ridging over the CONUS is finally pushed eastward for the weekend, with a trough amplifying over the Canadian Pacific Coast and crossing the northern Rockies and Plains. This wave arrives in the Northland Saturday into Sunday, with a surface low tracking eastward across the northern Plains, and pivoting toward Hudson Bay. Just how far north the low tracks remains in question, as model guidance diverges on track and where better moisture fields set up. Low level temps are unseasonably warm, with a significant warm nose expected. If moisture in in place, a mix of precip types is possible across the north at onset, and rain across most of the area by Saturday afternoon. A strong cold front arrives Saturday night, with a transition to snow into Sunday. Temperatures remain below normal through early next week.

AVIATION /06Z TAFS THROUGH 06Z THURSDAY/

Issued at 1147 PM CST Tue Dec 23 2025

VFR conditions expected to prevail through the TAF period under mid to high-level clouds and high pressure. A weak feature moving through this morning on the back side of the high pressure could bring a light wintry mix of snow or sleet (10-30% chance), primarily to northwest Wisconsin and the Minnesota Arrowhead. The highest potential is in the 24/08Z to 24/14Z timeframe, with PROB30 mentions at INL/HIB/DLH/HYR. There is a fairly prominent dry layer in the lower 5-7 kft of the atmosphere, so there is a decent chance precipitation may sublimate or evaporate prior to reaching the ground. Winds remain at or under 10 kt throughout the TAF period. Strong south-southwest winds around 35kts aloft will bring a period of LLWS for HIB/INL/BRD, generally between 24/09z and 24/15z.

MARINE

Issued at 156 PM CST Tue Dec 23 2025

Strong northwest winds will continue to diminish through the afternoon and evening, as high pressure arrives from the west. After a fairly benign day Wednesday, stronger northeasterly to easterly winds move in Thursday. Looking ahead, there are chances for more strong winds through the weekend with another passing system.

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...None.