textproduct: Duluth

KEY MESSAGES

- The potential for heavy snow has expanded to all of northwest Wisconsin and the I-35 corridor in Minnesota, with lighter snowfall amounts to the west and north.

- Sharply colder temperatures and strong winds arrive Sunday with wind chills dropping well below twenty degrees below zero by Sunday night with strong northwest winds.

DISCUSSION

Issued at 514 AM CST Sat Dec 27 2025

Current Conditions/This Morning:

We continue to get little waves of showers moving across northern Minnesota this morning, which have the potential to lay down areas of icing on roads and elevated surfaces. On top of that, we have a large area of fog over much of the Northland, which may also lay down some ice, producing slippery roads for this morning's commute. The Winter Weather Advisory issued by the evening shift has been extended through noon today, thinking that during the afternoon hours air temperatures rise above freezing and ice accumulations stop and we can let it drop. Have left the Fog advisory as is, but we are likely to see reduced visibilities through much of the day today, even if they are not as low as they are now.

Sunday into Monday:

This storm, which we have been watching for several days has suddenly gotten rather interesting. The surface low track in the models has become more consistent from both a run to run and model to model perspective, and shows a dramatic strengthening trend from noon Sunday through noon Monday. The surface low should develop over eastern Colorado today, then move east across the plains to cross northern MO into IL Sunday, then into lower MI and across Lake Huron Sunday night into Monday morning. This system will not only have an inverted trough that extends up into the region, but should also develop a nice TROWAL over MN and WI Sunday night into early Monday. The whole system appears significantly stronger than it did yesterday morning, with the low pressure center deepening more quickly and getting deeper by 12z Monday than on previous runs, and within the ensembles, more members are getting deeper than they were before. This has served to push more moisture and lift in our direction, increasing winds and precipitation amounts in the Sunday night into Monday time frame. In addition, we will have more lake effects to work with, enhancing snowfall totals all along the South Shore, where before they were limited to mainly Ashland and Iron counties. With that, have expanded the Winter Storm Watch to all of northwest Wisconsin, plus Pine and the Carlton/South St. Louis zone, with precipitation beginning as early as 15z Sunday, and lingering until 18z Sunday. I anticipate we will need Advisories into the Brainerd Lakes and along the Iron Range as well. The cold air moving in behind this system will cause temperatures to fall most of the day on Sunday, with overnight lows below zero Sunday night, and some single digit high temps on Monday. The strong winds with that cold air advection may also produce wind chill values in the 15 to 25 below zero range Monday morning.

Next Week:

Temperatures will remain near to below normal through the early part of next week. Another clipper will dive across the region on Tuesday, which may bring some light accumulating snow. There is another pool of cold air that slides into the area for the latter half of the work week. Ahead of this it looks like there will be another clipper, but this one may track to our south and not bring any snowfall to the area. Temperatures will be well below normal for Wednesday through Friday, with high temps in the single digits once again.

AVIATION /18Z TAFS THROUGH 18Z SUNDAY/

Issued at 1132 AM CST Sat Dec 27 2025

VLIFR to LIFR ceilings are largely expected through the next 12 hours as this very low stratus deck persists. Terminals that are seeing fog this afternoon are expected to keep fog and possibly even produce/drop back into dense fog after 23Z this evening. Expect winds to slowly shift southwesterly 03-09Z and help lift ceilings a bit and improve visibility. A period of heavy snowfall begins first in north-central Minnesota 12-15Z tomorrow and in northwest Wisconsin around 18Z.

MARINE

Issued at 1132 AM CST Sat Dec 27 2025

Update at 919 AM Originally Issued at 919 AM CST Sat Dec 27 2025

Update - The potential in storm force gusts near and just offshore of Grand Portage has increased where the previous Gale Watch has been upgraded to a Storm Watch this morning.

Southeast winds of 5 to 15 knots to produce generally quiet conditions on the lake today. A strong winter system moves across the lake Sunday through Monday, with an extended period of strong north-northwest winds for Sunday night and Monday before they diminish again late Monday and Monday night. Widespread gales are increasingly likely Sunday night and Monday. These strong winds are likely to build large waves, especially along the South Shore, along with concerns for freezing spray. Gale and Freezing Spray Watches are in effect for Sunday night through Monday.

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

DLH WATCHES/WARNINGS/ADVISORIES

MN...Dense Fog Advisory until 6 PM CST this evening for MNZ020-021- 037. Wind Advisory from 6 PM Sunday to 6 PM CST Monday for MNZ020. Winter Weather Advisory until noon CST today for MNZ010>012- 018-019-021-025-026. High Wind Warning from 6 PM Sunday to 6 PM CST Monday for MNZ021. Winter Storm Watch from Sunday morning through Monday morning for MNZ037-038. WI...Winter Storm Watch from Sunday morning through Monday morning for WIZ006-007. Winter Storm Watch from Sunday afternoon through Monday morning for WIZ001>004-008-009. MARINE...Gale Watch from Sunday evening through Monday evening for LSZ121-141>148-150. Storm Watch from Sunday evening through Monday evening for LSZ140. Heavy Freezing Spray Watch from Sunday evening through Monday evening for LSZ140-141-145>148-150. Dense Fog Advisory until 6 PM CST this evening for LSZ142. Wind Advisory from 6 PM Sunday to 6 PM CST Monday for LSZ142.