textproduct: Duluth

KEY MESSAGES

- A powerful and messy winter system is expected to bring heavy, wet snow, freezing rain, mixed precipitation, and strong winds to the Northland this evening to Thursday morning. Blizzard conditions are expected along the North Shore.

- Storm and Gale Warnings are posted for western Lake Superior starting Tuesday late afternoon from very strong easterly winds gusting to 55 knots.

DISCUSSION

Issued at 401 AM CST Tue Feb 17 2026

Current Conditions/Today:

Quiet this morning as with some mid level clouds moving overhead. The pressure gradient will continue to tighten through the day leading to an increase in winds out of the east flowing towards a strengthening low out west.

Winter Storm Set Up:

A deep trough over western CONUS has led to a strong polar front jet digging across the Four Corners and up into the Central Plains. This set up has spawned a low pressure in the Northern Rockies that will pivot through the Upper Midwest over the next couple days. The current flow of the atmosphere will allow this system to tap into moisture in the south Pacific as an atmospheric river is flowing into Baja. This moisture can already be seen at both the lower and upper levels of the atmosphere when viewing the ALPW. This influx of moisture is registering near the max of climatology for the GEFS with PWATS over 0.75" The low pressure strengthens to a noticeable 986mb which is near the minimum of CFSR reforecasts. Placement of the low track still oscillates a little with run to run of the models which is leading to some variability in the warm front placement.

Tuesday Evening and Night:

Winds and clouds will be increasing through the afternoon hours and we may even see some appreciable radar returns as well. However, it will take a little bit of time before we can saturate the column for precipitation to make it to the surface. The best chances ramp up after 6PM in the Brainerd Lakes region and spreads northeast overnight. We will initially have a stout warm nose aloft for most of the CWA with the exception being along the International Border and into the Arrowhead. Rain will be favored across the south with a wintry mix north and snow for far north. The warm nose will slowly sink south through the overnight period with snow becoming more dominant across northern MN. Strong FGEN circulations will likely lead to some banding snow with snowfall rates of 1-2" per hour at times. The North Shore in particular will see some terrain enhancement which could boost their snow rates up to 3" per hour.

With so much warm air lingering about in the atmosphere the sounding profiles show quite bit of riming. This will lead to dendrites clumping to supercooled water and lowering the SLR to 5:1 - 8:1. This will make for the wet heavy type of snow that feels like concrete to move and sticks extremely well to trees and power lines. As mentioned previously, this is expected to be a strong low pressure which will lead to very windy conditions. This creates several problems. The snowfall rates combined with the high winds will lead to white out conditions along the North Shore and near white out conditions elsewhere. Strong winds may also lead to snow loaded tree branches snapping and causing power outages.

One other interesting tidbit with this storm set up is the potential for some convective elements to arise. RAP is picking up on some MUCAPE of 300 J/kg with steep mid level lapse rates of 7-8C/km in the overnight period. This could manifest into a few storms or thundersnow at times. The convective component could also help drive some increased precipitation rates. Our instability parameters quickly drop off Wednesday morning.

Model trends and updates:

With this package update we have maintained the Blizzard Warning for the North Shore but there may be a need to expand this down into the Twin Ports. The 00Z run of the HREF showed increased probabilities of reduced visibility paired with stronger winds. The EFI for winds also increased over the Duluth area. If these trends hold on for the next model cycle an upgrade may be needed.

Looking at QPF plumes show an impressive floor for many of our locations in our Winter Storm Warnings. For example, Duluth has high clustering at the 1" mark and with our lower SLRs that would put the floor at around 7 inches. Going through these clusters we have updated our headlines. The Winter Watch has been canceled and filled in with Warnings for north St. Louis, Koochiching, and northern Itasca. Northern Cass, Southern Itasca, Aitkin, Ashland, and Iron have been added to and advisory. Interestingly enough you can kind of tease out where we expect our warm front to set up based on our winter weather headlines. Our Southern tier counties not in any headlines will be south of the warm front and experience largely rain with a rain snow mix at times.

Wednesday:

The worst conditions are by far expected to be Tuesday night when the heaviest precipitation is expected. Wednesday morning will see several changes compared to the overnight hours. The North Shore will still be seeing some impressive snowfall rates but should be working its way up towards Thunder Bay by mid morning. The current low track looks to introduce some dry air aloft wrapping around the system which may lead to some freezing drizzle or freezing rain. Better saturation works back in during the afternoon hours and the low pressure system is a slow mover so expect continued snow through the day with a rain/snow mix favored in NW WI. Colder air will be working its way in from the north which will allow for SLRs to increase closer to the classic 10:1 ratio leading to your more typical snow consistency.

Thursday/Friday:

Activity starts to taper off Thursday as the low pressure system fills over the Northland. Lingering snow showers are expected which will accumulate to another 1-2 inches. There does not look to much of a reprieve for the Northland as another system looks to work its way out of MO and up towards the Great Lakes on Friday. Timing and placement remain highly contested amongst the 00Z suite of deterministic guidance. But we should have enough cold air in place at this point in time that precipitation type should be all snow. Clustering of the low tracks currently suggests that NW WI would see the bulk of the activity. The NBM probabilities of 2 inches of snow for Friday presently sit around 40%.

AVIATION /18Z TAFS THROUGH 18Z WEDNESDAY/

Issued at 1140 AM CST Tue Feb 17 2026

Wind speeds and gusts were increasing a little faster than earlier forecasts. Think that trend will continue through the afternoon. Adjusted wind speeds and gusts accordingly. A long duration winter storm arrives tonight. Precipitation will start as rain or freezing rain at HIB and DLH before changing to snow. BRD will have rain or freezing rain changing to all snow Wednesday morning. HYR is expected to have rain until after 18Z Wednesday. Snow will be heavy in intensity and in water content. HIB and DLH will see the highest snow rates while INL and BRD will see lower snow rates. Low-level wind shear will be a factor in addition to the other hazards. A strong easterly low-level jet will develop tonight. The core of the jet will feature 65 to 75 knot winds. The strongest winds with the LLJ will be above 2kft AGL and centered around 3 to 4 thousand feet AGL.

MARINE /FOR NEARSHORE WATERS OF WESTERN LAKE SUPERIOR/

Issued at 401 AM CST Tue Feb 17 2026

Northeast winds today will continue increasing as a winter storm approaches from the west. Gale warnings begin at noon and a Storm Warning starts across the North Shore at 9PM. High snowfall rates are expected overnight leading to white out conditions. Storm force winds will taper off Wednesday afternoon but will likely still see gales into Thursday.

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

DLH WATCHES/WARNINGS/ADVISORIES

MN...Blizzard Warning from 9 PM this evening to noon CST Thursday for MNZ020-021. Winter Storm Warning from 6 PM this evening to noon CST Thursday for MNZ010-011-018-019-037. Winter Storm Warning from 9 PM this evening to noon CST Thursday for MNZ012. Winter Weather Advisory from 6 PM this evening to noon CST Thursday for MNZ025-026-035. WI...Winter Storm Warning from 6 PM this evening to noon CST Thursday for WIZ001-002. Winter Weather Advisory from 6 PM this evening to 6 PM CST Thursday for WIZ003-004. MARINE...Gale Warning from 3 PM this afternoon to 10 PM CST Wednesday for LSZ121-145>148-150. Storm Warning from 9 PM this evening to noon CST Wednesday for LSZ140>144. Gale Warning from 3 PM this afternoon to 9 PM CST this evening for LSZ142>144. Blizzard Warning from 9 PM this evening to noon CST Thursday for LSZ142.