textproduct: Duluth

KEY MESSAGES

- Heavy snow continues to move northeast tonight. Blizzard conditions are possible along the South Shore. Gusty winds also expected elsewhere could lead to blowing snow.

- Snow enhancement from a gravity wave and lake effect snow will lead to higher snow totals across northwest Wisconsin, particularly at higher elevations.

- After this system, cooler air is here to stay for the rest of the forecast period. Highs will be in the 20s and lows in the teens for the rest of the week. Low temperatures near zero are expected Sunday night.

UPDATE

Issued at 559 PM CST Tue Nov 25 2025

Increased winds with this latest forecast update. Guidance is showing a strong pressure gradient across the region boosting the overall gust potential with this winter storm. Snow continues to slowly overtake the region with radar showing areas of enhanced KDP in the Brainerd Lakes region. Looking at webcams shows large dendrites in the area which coincides with the strongest omega values located in the DGZ. At this time we don't anticipate expanding the blizzard warning but the favorable forcing and increased winds may lead to periods of whiteout conditions.

DISCUSSION

Issued at 211 PM CST Tue Nov 25 2025

This large low pressure system, currently located over southern Minnesota, continues to make its way northeast towards the Northland. This system is already producing snow across eastern ND/SD with visibilities less than a mile. If those conditions continue, some additional Blizzard Warnings may be needed for portions of the Northland. Particularly, as we head into this evening, a band of frontogenesis combined with strong forcing and divergence is expected to strengthen further this band of enhanced snowfall in the TROWAL region of the system. It has shifted south again, leading the placement of this band to likely be mostly over NW Wisconsin, and possibly just clipping the North Shore. Additionally, as flow begins to turn to the northwest, CAMS are showing a potential for a gravity wave to set up over Douglas/Bayfield counties, which could lead to over an inch per hour rates at times in localized areas. This setup can keep this gravity wave going as late as Wednesday afternoon. The snowfall rates (around 1"/hr) and winds will be sufficient for meeting a blizzard warning criteria, but whether the visibility is lowered to below a quarter mile for an extended period of time is still uncertain in these areas with the exception of Douglas and Bayfield counties. With the gravity wave, confidence is higher for those higher snowfall rates and, as a result, visibilities below a quarter mile. Blizzard Warnings have been issued for both counties.

A break in the snowfall may be seen in our southern line of WI counties this evening into tonight as the dry slot moves east just to our south. The exact track of the dry line should stay largely to the south, so a break in precipitation, if any, should be brief.

Early Wednesday morning, as winds shift further to the northwest, lake effect snow will also begin over northwest Wisconsin. Since we have had temperatures averaging above normal for the last few weeks, Lake Superior water temperature is still in the 40s. With the CAA, the air mass will be much colder than the water, which will enhance the lake effect snow further along with sufficient mid level lapse rates increasing throughout the morning (6-9 C/km). As with Douglas and Bayfield counties, confidence has increased that the combination of enhanced snowfall rates (>= 1"/hr) and wind gusts will create visibilities less than a quarter mile for an extended period of time. So, Blizzard Warnings have been issued for Ashland and Iron counties as well. Snowfall across the region will begin to exit Wednesday morning, but lake effect snow will continue for Ashland and Iron counties through Wednesday and into the latter half of the week.

Overall, a majority of the area will see an additional 6"+ except for west of Ely down to Brainerd. Areas under the TROWAL could see up to a foot of snow, and the gravity wave/lake enhancement across the South Shore counties will lead to 10-15 for most, with bullseyes of 20"+ in northern Iron County. Since snowfall has shifted south again, and some areas are not seeing snow as far north as previously forecasted, opted to end the Winter Weather Advisory for Koochiching county and downgraded the Winter Storm Warnings for northern Itasca and northern St. Louis counties to Winter Weather Advisories.

Winds throughout the system will be strong as well, increasing initially from the northeast before backing to the northwest. Gusts up to 35 mph are expected for most, especially on Wednesday. The North and South Shores could see wind gusts upwards of 45 mph overnight and Wednesday with the most intense CAA into the region. These elevated winds could lead to any snow that hasn't already compacted to be blown around. A cool down is also expected behind the system, where we will have temperatures below freezing for the rest of the forecast period. High temperatures will be in the twenties and possibly even the teens by next week, and lows will be in the teens decreasing to around zero next week as well.

There is the potential for another system to bring light snow this weekend. Global models have started to have better agreement on the track of the system, which is currently to our south. Most of the moisture and forcing will remain south as well, so any snow accumulations are expected to be light with the current forecast. Light lake effect snow on the back of this system is looking likely as well.

AVIATION /06Z TAFS THROUGH 06Z THURSDAY/

Issued at 1147 PM CST Tue Nov 25 2025

A Winter Storm continues across the Northland tonight, with widespread snowfall and strong north to northwest winds. The back edge of the snowfall is roughly from INL to BWP, with light snow at INL and BRD. Heaviest snowfall is currently falling at DLH and HYR, where better dynamics is crossing the region. A mix of MVFR and IFR cigs are being overshadowed by reduced vis of 1/4mi to 1mi due to blowing snow.

For the rest of tonight, the back edge of the snow will slide eastward, with snow tapering off at INL and BRD by sunrise, leaving scattered showers possible for a few hours. Heavy snowfall will continue at DLH and HYR. HIB is on the edge of heavier banding, and might have occasional heavier snow showers. North to northwest winds will remain elevated, with gusts of 30-40kt at most terminals, resulting in blowing snow and vis reductions. Winds will be slightly weaker at INL with gusts of 25kts.

Conditions slowly improve Wednesday with the system pulling east and snowfall tapering off on the MN side through the morning hours. Lake effect snow showers will persist through the tomorrow leading to a prolonged period of snow and lower ceilings at HYR.

MARINE /FOR NEAR SHORE WATERS OF WESTERN LAKE SUPERIOR/

Issued at 211 PM CST Tue Nov 25 2025

Winds continue to increase this afternoon over Lake Superior as the system bringing heavy snow approaches. First, winds will be out of the northeast today and this evening, then backing to the northwest overnight tonight. Gusts upwards of 40 kts are expected, especially tonight into Wednesday. Waves will continue to builds as well, reaching 7-10 ft along the South Shore by this evening and increasing to 10-15 ft around the Apostles and Bayfield Peninsula overnight. Gale Warnings are in effect for all western Lake Superior near shore waters into Thursday morning.

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 until 6 AM CST Wednesday for MNZ011- 018. Winter Storm Warning until midnight CST Wednesday night for MNZ012-019>021-037. Winter Storm Warning until noon CST Wednesday for MNZ025-026- 033>036. Winter Storm Warning until 6 PM CST Wednesday for MNZ038. WI...Winter Storm Warning until midnight CST Wednesday night for WIZ006>009. Blizzard Warning until midnight CST Wednesday night for WIZ001- 002. Blizzard Warning until 6 AM CST Thursday for WIZ003-004. MARINE...Gale Warning until 6 AM CST Thursday for LSZ121-140>148-150.