textproduct: Duluth

KEY MESSAGES

- Multiple rounds of strong winds are expected through this week: Tuesday afternoon and evening (west to northwest direction, Wind Advisory in effect), Wednesday afternoon and evening (southerly, not quite as strong), and through the day Thursday (northwest, likely strongest of the week).

- A messy system could bring rain, freezing drizzle, and heavy wet snow to the Northland Wednesday afternoon through Thursday. Uncertainty is still high on exact placement of particular sensible weather impacts.

- Temperatures warm above freezing Tuesday and again Wednesday evening/early Thursday morning before crashing back down below zero by Friday morning.

DISCUSSION

Issued at 318 PM CST Mon Dec 15 2025

A fairly quiet, mostly sunny afternoon with near average temperatures should be enjoyed today, as this tranquility will not be the norm for the rest of the week. Several back to back low pressure systems are expected to move along the Canadian Border with tight pressure gradients and ample moisture sources.

The first system tomorrow passes to our north and brings a mostly dry front across the area through the day, bringing a quick blast of northwest winds on the backside screaming across the Northland. Gusts of 25 to 45 mph are expected, possibly over 50mph on the North Shore. A Wind Advisory has been issued for portions of north-central MN and the North Shore from Tuesday afternoon through Tuesday evening or early Wednesday morning. Along the North Shore, there is a non-zero chance for gusts over 60mph, which, if they materialize, could warrant the need for an upgrade to a High Wind Warning there. Those winds should calm quickly into Wednesday morning.

This Tuesday system will provide stout WAA tomorrow and should allow temperatures to skyrocket well above normal, with afternoon high temperatures in the upper 30s to low 40s. With such a well-chilled snowpack, there likely wont be too much widespread melting, but areas that see some melt on sidewalks and roads could lead to slick spots as temperatures go back below freezing overnight.

The highlight system of the week pushes into the area Wednesday, keeping the above normal temperatures going as we likely stay in the warm sector ahead of this low. Due to the timing of this system, the high temperature on Wednesday and Thursday will likely be non- diurnal and close to each other around midnight, so we'll warm through most of the day Wednesday and cool through the whole day on Thursday.

This Wed-Thu system is robust for one on a clipper-like track, as most solutions show a central pressure less than 980-990mb and NAEFS and ECE are at the bottom of climatology for mean MSLP percentiles. It should also have multiple moisture sources as it pulls from the atmospheric rivers hitting the Pacific Northwest and manages to access Gulf moisture as well. This system will likely be able to produce heavy wet snow and very strong winds. However there are currently several different clusters of solutions when it comes to the track of this system that will affect our sensible weather. A more northerly track option (Euro Ensemble, some Canadian ensemble members) would keep much of the heavy precipitation to our north, with a rain/snow mix along the warm front Wednesday PM and then a significant dry slot into Thursday (possible freezing drizzle) before some light snow arrived on the backside along with plunging temperatures. A more southerly track (GEFS ensemble and some Canadian members along with Euro AI ensemble) would pull more of the precipitation shield into our area with a heavy snow potential across the north. Either way we'll likely see some rain/snow mix beginning late Wednesday afternoon that transitions into all snow by Thursday afternoon, possibly with a period of freezing drizzle in between. Currently the best chance for a couple inches or more of snow is along the International Border. As this system pushes east Thursday PM, temperatures will plunge back below zero by Friday morning. Depending on exactly what kind of precipitation any given area receives some icy slick spots could develop.

Southerly winds pick up through the day Wednesday, but compared to Tuesday and Thursday these will be more on the "blustery" side with gusts of 20-30mph. Those winds turn westerly Wednesday evening into Thursday, and some of the strongest winds of the week are expected through the day Thursday out of the west-northwest. Widespread gusts of 30-45mph are likely with stronger winds along the North Shore. Another round of Wind Advisories could be needed if not superseded by winter headlines.

Don't worry, the active weather is done after Thursday. We should see a very brief lull in activity overnight into Friday morning before another clipper passes over us, bringing a chance for some light snow accumulations. Onshore winds along the North Shore could lead to some enhanced amounts there but that will be very dependent on exact track which is still uncertain at this time.

AVIATION /00Z TAFS THROUGH 00Z WEDNESDAY/

Issued at 602 PM CST Mon Dec 15 2025

Satellite and surface observations show an area of MVFR stratus building into INL and eventually HIB this evening and early tonight, but should see some improvements back to VFR towards morning. Warm flow in the lower levels of the atmosphere may support some additional low cloud (SCT to BKN MVFR to possibly IFR ceilings tonight), but confidence is not high at the moment. There may be a brief one to two hours of light freezing drizzle at INL and HIB, and possibly BRD/DLH to a lesser extent tonight into early Tuesday morning, with PROB30s currently highlight timing of best potential. Low-level moisture is shallow and there may not be enough of it to see any precipitation. Winds become gusty into Tuesday, becoming southwesterly in the morning, westerly in the afternoon, and northwesterly Tuesday evening. Wind gusts of 25-35 kt are forecast for daytime Tuesday, strongest late in the period. Low-level wind shear becomes widespread starting tonight.

MARINE /FOR NEAR SHORE WATERS OF WESTERN LAKE SUPERIOR/

Issued at 811 PM CST Mon Dec 15 2025

Only slight adjustments were made to wind and wave forecasts for tonight through Wednesday. The main change to the forecast was to add Small Craft Advisories in for western Lake Superior nearshore waters ahead starting early Tuesday morning ahead of the Gale Warnings. Winds and gusts will initially ramp up out of the southwest before turning westerly late Tuesday afternoon and evening.

Previous Discussion: Numerous rounds of gales and possibly storm force winds are expected through this week. The first round arrives Tuesday afternoon and evening with northwest winds behind a mostly dry cold front. The strongest winds should be along the North Shore but all of Western Lake Superior will likely see gusts in excess of 35 knots. Gusts in excess of 45 knots are possible for the North Shore. A Gale Warning is in effect. Wind should die fairly quickly going into Wednesday morning but the lull wont last long, with southerly winds picking up through Wednesday afternoon. Another period of gale force gusts is possible here too. Into Thursday morning those winds remain strong but become northwesterly and strengthen even further. By Thursday afternoon and evening gale force winds are likely and storm force gusts are possible, especially for the North Shore. Winds should calm going into Friday morning. Additional Gale Warnings and Heavy Freezing Spray Warnings will likely be needed, especially for Thursday.

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

DLH WATCHES/WARNINGS/ADVISORIES

MN...Wind Advisory from 2 PM to 9 PM CST Tuesday for MNZ010-011-018. Wind Advisory from 5 PM Tuesday to 3 AM CST Wednesday for MNZ020-021. WI...None. MARINE...Small Craft Advisory from 6 AM Tuesday to 6 AM CST Wednesday for LSZ121-148. Small Craft Advisory from 3 AM to 6 AM CST Tuesday for LSZ140- 141. Gale Warning from 6 AM Tuesday to 6 AM CST Wednesday for LSZ140-141. Small Craft Advisory from 4 AM to 6 PM CST Tuesday for LSZ142>145. Gale Warning from 6 PM Tuesday to midnight CST Tuesday night for LSZ142>145. Small Craft Advisory from 4 AM to 10 AM CST Tuesday for LSZ146- 147-150. Gale Warning from 10 AM Tuesday to midnight CST Tuesday night for LSZ146-147-150.