textproduct: Duluth

KEY MESSAGES

- Extremely dangerous cold temperatures are expected through the weekend, with multiple days below zero.

- Scattered snow showers, with visibility as low as 1/4 mile, are expected through this evening. Visibility and driving conditions may change rapidly.

- Light lake effect snow and clouds may persist along the South Shore into the weekend.

DISCUSSION

Issued at 335 PM CST Wed Jan 21 2026

Not many changes to the going forecast this afternoon. Snow showers over the Northland in the wake of the cold front appear to be benefiting from a little more low-level instability than we expected earlier. As a result we're seeing horizontal convective rolls and snow showers with visibility of 1/2 to 1/4 mile at times. Tossed out and SPS to convey our concern.

A possible mesolow developed over eastern North Dakota this afternoon with a secondary convergence boundary advancing southeastward into the ND/MN border area. From the mesolow south-southwestward locally enhanced convective snow showers developed. The line of convective showers extended into northwest South Dakota. I see no reason that feature and the localized enhanced snow showers will weaken before 00Z or even 02Z. As a result portions of central Minnesota may experience a brief burst of heavy snow with visibility less than 1/4 mile. Snow squalls certainly seem possible in this scenario.

Dangerous wind chills are forecast starting tonight and will persist through Saturday morning. The airmass forecast for Thursday night through Saturday morning is the coldest our area experienced since around 2021. January 2019 is another analog. We upgraded the Extreme Cold Watch Thursday night and Friday morning to a warning with this update. The Extreme Cold Watch remains in effect from 17Z Friday until Saturday morning. While those air temperatures will be the coldest of this stretch, surface high pressure passing just to our south will limit wind speeds overnight. That said, if we have clear skies and light winds, ambient air temperatures will make a run at -35 to -45 degrees, which would warrant warnings regardless of wind.

For additional details, please see the excellent discussion from this morning below.

Previous Discussion Issued at 344 AM CST Wed Jan 21 2026...

Clipper With Light Snow Today - Early Thursday:

Seeing some light snow showers this morning as some weak surface/mid-level troughing moves across the Northland coupled with a mostly saturated atmospheric profile, the lowest few thousand feet of which are located in the dendritic growth zone. There may be a couple hour break in snow for NE MN around sunrise early this morning and in northwest Wisconsin mid morning before additional shortwave energy associated with another approaching Clipper system brings in widespread snow from the northwest today along and behind a front. Some wrap around light snow is expected into at least this evening behind the front, with additional shortwave energy possibly keeping the light snow going into Thursday morning. Around 1-1.5" or less are forecast for the region, with the lowest amounts around 0.5" in far northern Minnesota.

Temperatures will be relatively mild today, with highs topping out in the teens, though wind chills will remain in the single digits above and below zero. Gusty northwest winds move in behind the front this afternoon into tonight, starting the trend of substantially colder air for the next several days beginning tonight.

Extremely Dangerous Cold Late This Week - Weekend:

A brutally cold arctic airmass is expected to work over the northern CONUS behind the departing Clipper and cold front tonight through this weekend as 850 mb temperatures drop into the -20s to -30s degC tonight through Sunday night. At the ground, this will translate to a prolonged period of temperatures below 0F for most locations in the Northland from Thursday through Monday morning. Northwest winds will initially be breezy for Thursday into midday Friday, resulting in the coldest wind chills being in the late Thursday into midday Friday timeframe, when wind chills of -40F to -55F will be possible. Even a few mph stronger wind gusts than the current forecast could push these wind chills even colder! Winds eventually weaken later Friday into this weekend as the deep high pressure--possibly as strong as 1048 mb--slides through. For context, this strong of a high pressure is near the maximum of the NAEFS CFSR reanalysis climatology for this time of year. The coldest actual air temperatures (not wind chills) will be Friday night into Saturday morning, and lows of -30F to -40F for areas away from Lake Superior. Near-Lake Superior locations should be slightly less cold in the -20s. There is a 20% chance that the low temperatures Saturday morning could dip below -40F in far northern Minnesota.

Several cold weather headlines have been issued given high confidence in this extremely dangerous cold spell occurring. For tonight through daytime Thursday, we have issued a Cold Weather Advisory for most of central to northeast Minnesota and an Extreme Cold Warning for far northern Minnesota. The southern extent of the Cold Weather Advisory was expanded south due to a limited period of daytime moderation to the temperatures/wind chills before they come crashing down again late in the day Thursday into Thursday night. Northwest Wisconsin was left out of the Cold Weather Advisory for tonight/Thursday morning due less cold lows in the single digits below zero largely keeping wind chills there warmer than -25F. Starting Thursday evening and persisting through midday Saturday, the entirety of the Northland has been placed under an Extreme Cold Watch as limited daytime moderation in wind chills is expected for Friday. The expectation of light winds and slightly less cold days on Sunday into Monday morning should more likely place those days in the wind chill range for Cold Weather Advisories relative to the brutally cold days on Friday and Saturday.

South Shore Light Lake Effect Snow:

The very cold 850 mb temperatures/airmass late this week and weekend should keep light lake effect going for the South Shore. Given how dry the airmass is expected to be--PWATs of around 0.05" or less, near the bottom of climatology--expect snow rates to remain light.

Next Week:

We do see some relatively "warmer" temperatures heading into next week, though temperatures will still be below normal through the end of the month. Expect highs in the single digits to teens above zero and lows largely in the single digits below zero. Can't rule out some periodic South Shore light lake effect snow continuing into next week. Otherwise, don't expect much if anything in the way of accumulating snow for the Northland late this week into early next week. Global model ensembles do hint at a Clipper system moving through the Upper Midwest region sometime in the next Tuesday night to next Thursday timeframe, but confidence in timing and snowfall amounts with that system remains low.

AVIATION /06Z TAFS THROUGH 06Z FRIDAY/

Issued at 1149 PM CST Wed Jan 21 2026

Expect some breaks in the clouds and VFR conditions for several hours this evening. Clouds will move in from the west in the next 3 to 6 hours though, and MVFR ceilings can be expected at times along with temporary MVFR visibilities in scattered snow showers. Coverage of clouds is generally broken, and thus ceilings and visibility are likely to be variable between VFR/MVFR through the morning. Temporary IFR ceilings can't be ruled out either. All of this is associated with a strong cold front passing through and post-cold frontal low-level convection. Expect winds to increase in speed from the northwest as well with gusts to around 20 kt Thursday afternoon. Flurries may be possible through the day, but coverage of flurries and clouds in general should start to diminish some in the afternoon.

MARINE /FOR NEARSHORE WATERS OF WESTERN LAKE SUPERIOR/

Issued at 335 PM CST Wed Jan 21 2026

Westerly and northwesterly winds are forecast tonight and will strengthen in the wake of a cold front which passed over the waters this afternoon. Conditions will become hazardous to smaller vessels over western Lake Superior. The combination of wind, cold air temperatures, and waves will raise the risk of heavy freezing spray over the Outer Apostle Islands tonight. The heavy freezing spray risk will increase Thursday from Duluth to Bayfield. Wind and waves will gradually decrease Saturday morning ending the risk to smaller vessels and heavy freezing spray.

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 until 3 PM CST Thursday for MNZ018>021- 025-026-033>037. Extreme Cold Warning from 3 PM Thursday to 11 AM CST Friday for MNZ018>021-025-026-033>038. Extreme Cold Watch from Friday morning through Saturday morning for MNZ010>012-018>021-025-026-033>038. Extreme Cold Warning until 11 AM CST Friday for MNZ010>012. WI...Extreme Cold Watch from Friday morning through Saturday morning for WIZ001>004-006>009. Extreme Cold Warning from 6 PM Thursday to 11 AM CST Friday for WIZ001>004-006>009. MARINE...Small Craft Advisory until 4 PM CST Friday for LSZ140>148-150. Cold Weather Advisory until 3 PM CST Thursday for LSZ142. Extreme Cold Warning from 3 PM Thursday to 11 AM CST Friday for LSZ142. Extreme Cold Watch from Friday morning through Saturday morning for LSZ142. Heavy Freezing Spray Warning from 4 PM Thursday to 4 AM CST Friday for LSZ145>147. Heavy Freezing Spray Warning until 10 AM CST Friday for LSZ150.