textproduct: Duluth

KEY MESSAGES

- A Winter Weather Advisory has been issued for the Arrowhead Monday late morning through Monday night for 2 to 5 inches of snow. Around 1 to 3 inches of snow are expected elsewhere.

- More snow is expected Tuesday afternoon through early Wednesday with potential for widespread accumulating snow and difficult travel possible for the Tuesday afternoon and early Wednesday morning commute.

- Additional light snow episodes are possible late-week into next weekend along with cold air and below-zero temperatures likely at night.

DISCUSSION

Issued at 215 PM CST Sun Dec 7 2025

Pretty quiet weather out there this afternoon. There are some lake-effect clouds in northwest wind affecting parts of NW Wisconsin. Little impacts are expected from that with drier air moving in from the west/northwest into tonightjust a bit of light snow possible with minor accumulations. A very quick clipper passes by to our south tonight as well. Some flurries could graze north-central Minnesota.

Clipper #1: Attention turns to the first clipper that moves in late Monday afternoon and drops some light to perhaps occasionally moderate snow Monday night, quickly moving out early Tuesday morning. This is still looking like largely a 1-3 event, but some places (especially in northeast Minnesota, particularly the Arrowhead) could see some 4 to maybe 5 totals by Tuesday morning as a lake-effect snow band moves onshore during Monday morning. This will likely be mainly a shore-parallel lake-effect band, so areas right along the shore from roughly Grand Marais to Grand Portage will have the best chance of seeing some of those locally higher totals. We did decide to issue Winter Weather Advisories for the Arrowhead for the possibility for some of these higher amounts. Its possible that some localized amounts to 4 could happen for parts of Koochiching, North St. Louis, and Central St. Louis counties as well, but confidence is not high enough that advisory-level snows will fall at this time, so headlines were not issued there. All-in-all, a quick-hitting clipper.

Clipper #2: The next clipper arrives Tuesday afternoon with some more snow that should affect the evening commute. Still dealing with some storm track differences among ensemble members with this one, but generally it does continue to look more intense and more capable of producing more widespread advisory snowfall amounts for a good portion of the Northland. Some strong ascent associated with warm air advection and frontogenesis ahead of the low will likely produce a narrow band of higher snowfall totals/rates Tuesday evening that could lead to some localized ~6 snowfall amounts. Where that happens could be anywhere between Duluth and Hinckley and points roughly west-northwest and east-southeast of that general line. Confidence is only 30-50% that such high totals (6 or more) could happen there, and wherever they do happen will probably be in a narrow swath. With such uncertainty still remaining, and also considering the fact that we have the first clipper to deal with first, we decided not to issue any Winter Storm Watches with this update. If we were to do so, we would have to issue for too broad of an area. Most likely, widespread Winter Weather Advisories will be needed. Other factors influencing the decision not to issue a Winter Storm Watch are that winds are not expected to be very strong (a bit breezy, but it shouldnt cause widespread blowing snow), and extreme cold is not expected to be a factor either. If models do come into better agreement on a location for this potentially locally heavier snow band, and if snowfall amounts around or slightly in excess of 6 remain possible, then additional headlines may be considered in later updates. The best vertical ascent will be for several hours Tuesday evening, and snowfall rates could reach around 1/hr for a few hours, yielding the ~3-6 totals for many areas. Travel will likely become difficult for the Tuesday evening commute and possibly lingering into Wednesday morning. This second clipper will move out Wednesday morning. Some lake-effect will probably persist along the South Shore as winds turn north to northwesterly. Some additional light accumulations will be possible there into Wednesday night.

More Clippers? Following the departure of the second system on Wednesday, we are monitoring the potential for a third, weaker clipper late in the week, though the track of that system remains uncertain. Regardless, as these systems pass through, models suggest dominant northwest flow, ushering arctic air into the region for the weekend with lows potentially dropping well below zero overnight again. Lake-effect will likely become a bit more persistent along the South Shore as well later this week into the weekend with all these clippers and cold air passing through to keep the lake machine agitated.

AVIATION /06Z TAFS THROUGH 06Z TUESDAY/

Issued at 1203 AM CST Sun Dec 7 2025

An area of light snow over west-central to southern Minnesota will drift southeastward and weaken by 12Z. Snow flurries with VFR visibility and ceilings are forecast between 07Z and around 14Z. Otherwise the main focus of the forecast is a clipper system moving into the region this afternoon. A period of snow is expected with that clipper starting at INL and BRD around 20Z. A period of IFR/LIFR conditions are forecast. Timing those lower conditions may fluctuate a little. Handling with PROB30s for now. Low-level wind shear will be a concern at BRD after 20Z. Winds aloft will increase at HIB, DLH, and HYR also, although should remain less than the LLWS criteria.

MARINE /FOR NEAR SHORE WATERS OF WESTERN LAKE SUPERIOR/

Issued at 215 PM CST Sun Dec 7 2025

Southwest winds will ramp up on Monday ahead of the first clipper system. Small Craft Advisories have been issued as gusts are expected to approach 25 to 30 knots and waves build to 3 to 5 feet, particularly along the North Shore and Outer Apostle Islands. Winds briefly lessen going into Tuesday morning. Then, as another clipper system moves in Tuesday afternoon, expect gusty northeast winds to develop, which will likely cause hazardous conditions for small craft. There is a a 20 to 60 percent chance of gales (gusts over 34 knots) on Wednesday morning as winds shift northerly behind the departing low.

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

DLH WATCHES/WARNINGS/ADVISORIES

MN...Winter Weather Advisory from 3 PM Monday to 6 AM CST Tuesday for MNZ012-020. Winter Weather Advisory from 9 AM Monday to 6 AM CST Tuesday for MNZ021. WI...None. MARINE...Small Craft Advisory from 9 AM Monday to 3 AM CST Tuesday for LSZ121-140>148-150.