textproduct: Duluth

KEY MESSAGES

- Light snow accumulations are expected through the day Friday. Totals of a tenth to around an inch are possible, locally higher for the South Shore.

- Strong northwest winds are expected behind the snow Friday afternoon through Saturday morning. Much of the Northland should see gusts of 25 to 35 mph, while the North Shore could see gusts of 30 to 45 mph and a Wind Advisory may be needed.

- Much colder temperatures are expected for this weekend, with the coldest conditions on Saturday. Actual temperatures will struggle to get above zero while wind chills remain in the teens to 20 below zero, with even colder values into the negative 20s and 30s overnight. A Cold Weather Advisory has been issued.

DISCUSSION

Issued at 311 PM CST Thu Dec 11 2025

A clipper system passing to our south this afternoon has contributed to some clouds across the Northland and flurries for portions of north-central MN. Flurries should diminish through the evening but mostly overcast skies will likely stick around. A clipper pushes over the Canadian Prairie and brushes over the Upper Great Lakes tomorrow into the weekend, bringing chances for some light snow and dragging cold air into the region.

Light accumulating snow should push across the Northland from west to east through the day Friday, beginning in the early morning hours. We're not expecting much out of this, mostly a couple tenths for much of the region and up to an inch along the Borderlands and into the Arrowhead. Snow should wind down for most folks Friday afternoon and evening. Light lake effect snow will continue for the South Shore through the day Saturday, which could give them an extra inch.

As can sometimes be the case with clippers, a tighter pressure gradient on the backside of this system should bring some blustery northwest winds. These should arrive for north-central MN mid tomorrow morning and then push east along with the system through the day. Generally expecting winds of 10-25 mph with gusts of 25- 35mph, which could lead to some areas of blowing snow with the fresh light accumulations and an existing snowpack that doesn't have much of a crust yet. Along the North Shore, these northwest winds are expected to be enhanced, particularly Friday evening into early Saturday morning. As the cold front attached to the clipper system passes, a frontogenetical circulation should be able to set up parallel to the North Shore terrain ridge at the same time as katabatic downslope flow starts to accelerate - all of this on top of the zesty synoptic northwest winds. Have boosted our winds from Duluth to Grand Portage with many of the conceptual model boxes being ticked. The only thing that gave us some pause to not go much above 40-45mph with this update is that the front moves off fairly quickly, which could limit how long the downslope portion of the circulation is maximally enhanced. Still, hi-res guidance shows some suggestions of the highest gusts possibly being able to exceed 50mph between 6PM Friday to 3AM Saturday, and a Wind Advisory may be needed for coastal Lake and Cook County. Winds across the Northland remain breezy through the day Saturday before finally easing into and through the day Sunday.

As previously mentioned, Friday's clipper will pull behind it a leviathan of arctic air. Temperatures this weekend, especially Saturday, are expected to be frigid. Actual temperatures drop into the teens and 20s below zero for Saturday morning, and most of the area is projected to see highs stay negative during the day Saturday. Only those right along Lake Superior might be lucky enough to have a high temperature of positive 1-6F. Temperatures plunge again quickly Saturday night, with actual low temperatures back in the negative teens and 20s by Sunday morning. The brutal cold should ease somewhat Sunday, with highs returning to the single digits above zero. With brisk northwest winds, wind chill values will remain very cold all weekend. Overnight wind chills in the negative 20s and 30s are likely, and daytime wind chills will struggle to warm into the negative teens. Have opted to put the entire CWA in a Cold Weather Advisory beginning midnight Saturday through Sunday mid morning. Despite warming up slightly above our true criteria during the day Saturday, this is the first truly frigid airmass of the season, and many folks are attending or organizing holiday activities, so have opted to stay on the lenient side.

Going into the work week, temperatures continue on the upswing of their ongoing rollercoaster ride. We'll go from temperatures being 20 to 30 degrees BELOW normal on Saturday to being 10 to 20 degrees ABOVE normal on Tuesday, as highs are projected to rise above freezing Tuesday afternoon, thanks to weak ridging and zonal flow pulling warmer air from the PNW. A system could brush our north Tuesday-Wednesday bringing some light precipitation to northern portions of the CWA. This more mild airmass then sticks around at least through midweek and global models continue to suggest a low pressure system pushing through mid to late week which could bring additional snow, and maybe a little rain, but there is still a very large dispersion in exact track/timing for this system.

AVIATION /00Z TAFS THROUGH 00Z SATURDAY/

Issued at 551 PM CST Thu Dec 11 2025

Mainly VFR conditions prevail this evening with light and variable to calm winds. There is some signal for fog/low stratus development for northwest Wisconsin late this evening into tonight prior to the snow, but will depend on how much clouds clear. A quick-hitting clipper system will bring 3-6 hours of light snow from west to east across the area starting overnight tonight and mostly exiting east of northwest Wisconsin by mid- afternoon on Friday. Conditions will largely be MVFR as snow passes through, but visibilities could dip to IFR for a couple hours when snow rates are the highest. INL could see some light lake- effect clouds/snow linger until around midday downwind of Lake of the Woods, however, given the cold air temperatures and partially open lake. Winds will be gusting to 20-30 kt out of the northwest in the wake of the snow, strongest along the North Shore and into DLH.

MARINE /FOR NEAR SHORE WATERS OF WESTERN LAKE SUPERIOR/

Issued at 857 PM CST Thu Dec 11 2025

No significant changes with this update. The forecast remains on track with winds rapidly ramping up out of the northwest on Friday into Saturday behind a passing cold front. Increasing waves along with strong winds and very cold temperatures could also lead to freezing spray along the South Shore from around Port Wing to the Outer Apostle Islands from late Friday afternoon into daytime Saturday.

Previous Discussion:

Fairly calm winds today should become southwesterly into Friday ahead of a passing front bringing light snowfall. As that front passes, much stronger northwest winds are expected to strengthen really quickly, especially along the North Shore where they will be enhanced by downslope flow. Have increased winds from late Friday afternoon through the day Saturday and issued a Gale Watch from 6pm Friday to 6PM Saturday. Would expect the strongest gusts to be Friday evening into early Saturday morning with isolated pockets of storm force gusts possible, most likely between Grand Marais and Silver Bay. Winds remain elevated through the day Saturday before weakening into the day Sunday. Lake effect snow bands are expected along the South Shore and in the open waters Saturday and Sunday with very cold temperatures, which may reduce visibility at times. Additionally, with very strong winds and very cold temperatures, some freezing spray may be possible.

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

DLH WATCHES/WARNINGS/ADVISORIES

MN...Cold Weather Advisory from 6 PM Friday to 10 AM CST Sunday for MNZ010>012-018>021-025-026-033>038. WI...Cold Weather Advisory from 6 PM Friday to 10 AM CST Sunday for WIZ001>004-006>009. MARINE...Gale Watch from Friday evening through Saturday afternoon for LSZ140>143.