textproduct: Duluth

KEY MESSAGES

- Mainly dry and warm today.

- Rain begins tonight before mixing with snow Tuesday then becoming all snow Tuesday afternoon. Snow will then continue Tuesday night and Wednesday before tapering off late Wednesday. Accumulating snow is expected for much of the Northland along with gusty winds leading to blowing snow.

- A strong lake-effect snowfall event is expected across Iron County Wednesday into Thursday. Snowfall totals in excess of a foot possible across the higher elevations.

- Temperatures plunge below normal behind this system with another large winter system possible for the weekend.

DISCUSSION

Issued at 412 AM CST Mon Nov 24 2025

Low pressure was located over northwestern Ontario early this morning with a warm front extending southeast across the Minnesota Arrowhead and western Lake Superior. A cold front trailed back into far northwestern Minnesota, North Dakota and Montana. Another area of low pressure was analyzed over east- central Colorado. Northward moving moisture ahead of this Colorado low will interact with the cold front sagging south across Minnesota into northern Wisconsin later this afternoon and tonight, leading to rain showers mainly across northwest Wisconsin tonight. Depending on where this front sets up, this shower activity may end up just to our south tonight. Highs today will reach into the 40s with a few low 50s in spots.

Attention then turns to the northern stream upper low moving out of the Northern Rockies and into the Upper Midwest on Tuesday. This will be the main weather maker for the Northland. Showers will spread across the region Tuesday with snow mixing in through the day as colder air starts to push in. A changeover to all snow is then expected late Tuesday with snow continuing into Wednesday before tapering off Wednesday night. Models have been fairly consistent with the low track across central Minnesota just to our south, keeping the Northland in the north side of the system. This will bring the deformation axis/TROWAL feature through the region which may lead to heavier snow amounts. There will be plenty of vertical motion that would likely lead to efficient dendritic growth rates as evidenced by the strongly negative Thaler QG omega progs. How long this strong vertical motion lasts could be an issue in how long these heavier snow conditions last. Snow ratios will also be a concern with snow starting out very heavy before ratios go up and snow becomes more powdery in nature as colder temperatures move in.

In terms of snow amounts, values have trended a bit higher with this update. This agrees with SREF plumes across the region. While there is still a bit a spread in the plumes, there is some clustering noted close to the mean. Currant amounts of 3 to 6 inches are likely across most of the Northland with higher amounts of 5 to 9 inches across the Iron Range into the Minnesota Arrowhead. Isolated higher amounts in the tip of the Arrowhead will be possible as well with less liquid precipitation expected. Over in northwest Wisconsin, 3 to 6 inches are expected across our southern tier of counties with 6 to 10 inches across the northern tier. Higher amounts will be possible across the Bayfield Peninsula back into central Douglas County due to the development of a gravity wave.

As for Iron County, heavy lake-effect snow is expected to follow the synoptic snowfall. This transition will occur on Wednesday morning as winds turn northwesterly as the low translates east of the region. The lake-effect snow will persist through Wednesday and Wednesday night before tapering off on Thursday as winds become more westerly. This looks to be a fairly significant event with surface to 850mb delta-T values of 15 to 20C and little shear expected. Snowfall totals in excess of a foot are expected along the higher elevations of the Gogebic and Penokee ranges with higher amounts approaching 2 feet possible in the usual heavy snow locations along Highway 77.

With all this said, the current Winter Storm Watch in place still looks good and no changes have been made with this forecast package. There was some consideration to expanding it across the remainder of our northwest Wisconsin counties, but with the highest accumulations limited to the far northern portions of Sawyer and Price counties, opted to leave them out with this update. However, should those higher amounts shift a bit more to the south, the watch will likely need to be expanded.

Aside from the lake-effect snow continuing across the South Shore for Thanksgiving, dry conditions are expected across the majority of the Northland. Highs Thursday will be in the 20s with lows falling into the low teens and single digits above zero for Thursday night/Friday morning. Looking ahead to the weekend, confidence is high that the cold temperatures will stick around. Models continue to advertise unsettled weather across the central CONUS during this time period as well. While currently most of the impacts look to remain south of the Northland, given the busy travel weekend, close attention will need to be paid as things could shift northward and lead to issues on the backside of the holiday as well.

AVIATION /18Z TAFS THROUGH 18Z TUESDAY/

Issued at 1119 AM CST Mon Nov 24 2025

VFR conditions persist for much of today. HYR will be the first to see ceilings lower tonight to MVFR around 06Z. All other terminals will follow throughout the night, with all reaching IFR (INL will remain MVFR) by Tuesday morning. Precipitation tomorrow will start as rain for southern terminals, but INL and HIB will already be around to below freezing, likely leading to snow from precipitation onset. DLH will likely make the transition to snow in the late morning.

MARINE /FOR NEAR SHORE WATERS OF WESTERN LAKE SUPERIOR/

Issued at 412 AM CST Mon Nov 24 2025

Southwesterly winds of 10 to 20 knots will be seen through much of the day today before turning northwesterly in the wake of a weak cold front late this afternoon. As low pressure begins to approach tonight, winds will turn northeasterly and become stronger at 10 to 15 knots with gusts to 20 to 25 knots by daybreak Tuesday. This will likely lead to conditions hazardous to small craft. Winds then further increase through the day Tuesday and become northwesterly with gales to 35 to 45 knots for Tuesday night into Wednesday night. Gale Watches are in effect for this time period. Winds will then slowly diminish Thursday into Thursday night with a period of conditions hazardous to small craft following the gales. Snow will lead to reduced visibilities as well starting Tuesday night and continuing into Wednesday night.

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

DLH WATCHES/WARNINGS/ADVISORIES

MN...Winter Storm Watch from Tuesday morning through Wednesday morning for MNZ010-018-025-026-033>036. Winter Storm Watch from Tuesday afternoon through Wednesday evening for MNZ011-012-019>021-037. WI...Winter Storm Watch from Tuesday evening through Wednesday evening for WIZ001-002. Winter Storm Watch from Tuesday evening through late Wednesday night for WIZ003-004. MARINE...Gale Watch from Tuesday evening through late Wednesday night for LSZ121-140>148-150.