textproduct: Duluth

KEY MESSAGES

- Areas of dense fog will persist through the morning before largely retreating to the North Shore and the Twin Ports area.

- Winter Weather Advisory for freezing drizzle continues. This may need to be extended into tonight as onshore flow does not let up until midnight

- Colorado Low for Friday will bring some thunderstorms and rain. Any snowpack that sees heavy rain or multiple storms may lead to ponding water in low-lying areas where ground is still frozen.

- Snow will filter in from the west with some freezing rain as cold air wraps around late Friday afternoon and evening. Total snow accumulations remain less then 2"

DISCUSSION

Issued at 326 AM CST Thu Mar 5 2026

Current Conditions:

Widespread dense fog and areas of freezing drizzle are the main highlights to start things off this Thursday morning. Rewinding a satellite loop all the way back to yesterday we can see the region being attacked on all fronts from stratus. Southerly winds across MN have a stratus deck that extends all the way into northern IA. More stratus was lingering across the International Border and into the Northern Plains. Yesterday afternoon we saw easterly winds overtake Lake Superior leading to more stratus and fog swooping in from the east. And now the region is largely blanketed with stratus and fog. The easterly winds off of Lake Superior have added some upslope component into the equation which has been capable of producing some drizzle. The cold air off the Lake quickly dropped temperatures to below freezing and this drizzle has led to some light ice accumulations.

Today:

Foggy conditions will linger through much of the morning before largely eroding across most of the region. However, easterly winds along Lake Superior will continue to share its influence with the neighboring land with at least a 60-80% chance of fog staying put in the Twin Ports and up the North Shore. Mixed in with this fog we will continue to see periods of drizzle. Our Winter Weather Advisory that was hoisted for freezing drizzle is set to expire at noon. Temperatures will still be borderline on the freezing mark and with onshore flow continuing this Advisory may need to be extended. The RAP 275K isentropic surface has been handling the freezing drizzle the best and it would suggest the ingredients will remain in play till midnight. The only mitigating factor may be the overall strength of the onshore flow which should diminish this afternoon but won't completely go away. This may only lead to freezing drizzle being less widespread and hanging closer to the shoreline.

Friday:

Widespread precipitation returns to the Northland as a Colorado Low moves into the Great Lakes Region. As is typical with these types of lows they will establish a gulf connection allowing for higher PWATs to be transported into the Northland. The deep moisture plume protrudes into NW WI with some PWATs around 1" placing it in the 99.5 percentile of the NAEFS climatology. With it still being March we will get to sample a little of everything across the Northland in regards to precipitation.

Activity may start as early as Friday morning where an inverted trough is projected to be moving across the Red River Valley and enter our western counties. Weak MUCAPE aloft could lead to a few rumbles of thunder in the morning but CAMs have really been waffling back and forth on producing anything with this boundary. The better forcing and precipitation chances arrive in the afternoon as the system moves into IA. The warm front will be advancing north through the day with ample isentropic forcing for ascent out ahead of it. Mid level lapse rates increase to 7C/km with some MUCAPEs around 100-200 J/kg. This pairing could produce some elevated thunderstorms. Severe weather is not expected at this time. The warm front looks to just barely stay out of the Northland with the better ingredients for severe weather staying south of us in the primary warm sector. Although it is worth noting, the latest HRRR run has the warm sector moving into Price county. The primary concern for this system will be how the rain interacts with our melting snowpack. This may lead to runoffs and ponding in low-lying areas where the ground remains frozen.

Cold air wrapping around the system will see snow start to fly across our north and northwest in the late afternoon and evening. There will likely be a few transitions zones of snow, snow/rain, freezing rain, and rain. These zones will continue to migrate east through the overnight period with snow eventually winning out by Saturday morning with the additional help of diurnal cooling. Snow amounts have trended down with the extreme outliers largely eliminated. Snow amounts are largely 2" or less. The best corridor for 1-2" extends from the Brainerd Lakes Region up through the Arrowhead and the North Shore including the Twin Ports.

Despite only being 48 hours out from the onset of the Colorado Low the two ensemble families of the GEFS and EPS still have some noticeable disagreements. While both have fair agreement on the low track through northern IA by Friday noon the spread thereafter is quite noticeable. The GEFS continues to remain the most aggressive with keeping the low strength and pulling large amounts of QPF into the region. QPF plumes have come down a bit on the GEFS side with the deterministic remaining the most extreme of the solutions. Timing and strength of the departure remain highly contested which is problematic due to some of the strongest synoptic forcing expected to move through in the overnight hours. An upper level trough will move in phase with the Low. This pairing along side a strong low level FGEN band setting up may lead to some banded precipitation. The question will be if this band sets up in the cold sector or the warm sector.

The Weekend and Monday:

The pattern still remains active through the weekend but impacts are not expected to be as widespread. Saturday morning will see the departure of the Friday system with high temps recovering back into the 40s. Warmer still as we move into Sunday with highs climbing into the 50s and possible 60s away from Lake Superior. A couple of low pressures moving across Canada may brush northern MN with some light rain/snow but model agreement remains low with the NBM only carrying around 20% for PoPs.

Tuesday:

Another system may be brewing for Tuesday. Cluster analysis has great agreement with a cut off low over Baja late Monday moving inland which may instigate some activity across central CONUS. Still a wide array of solutions in ensemble low tracks but most feature some low coming out of the Rockies. Track still remains highly variable.

AVIATION /18Z TAFS THROUGH 18Z FRIDAY/

Issued at 1145 AM CST Thu Mar 5 2026

Poor flying conditions will plague the terminals, particularly KDLH which is expected to stay mostly locked into LIFR visibility and ceilings due to persistent onshore flow and freezing fog - maybe a brief improvement this afternoon as the boundary layer gets mixed a little with daytime heating. Similarly other sites like KBRD and KHYR may see temporary improvements to MVFR this afternoon, but widespread IFR to LIFR conditions will return tonight. Expect east to southeast winds gusting up to 20 knots today, diminishing slightly overnight before rain spreads across all sites on Friday morning.

MARINE /FOR NEARSHORE WATERS OF WESTERN LAKE SUPERIOR/

Issued at 326 AM CST Thu Mar 5 2026

Enhanced easterly flow continues across Lake Superior with Small Crafts in effect until this afternoon. Fog has also engulfed the Lake and while the current expiration time is for this afternoon this may need to be extended. The latest model guidance is quite pessimistic and conditions may not improve until Friday when we see precipitation moving in from a Colorado Low. As this low departs on Saturday we will see some strong winds across the Lake once again as southwesterlies begin to stream. Gales will also be possible with the North Shore having the best chance at needing a Gale Warning.

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 midnight CST tonight for MNZ011- 012-019>021-037. WI...Winter Weather Advisory until midnight CST tonight for WIZ001- 002. MARINE...Dense Fog Advisory until noon CST today for LSZ140>146-148-150. Small Craft Advisory until 4 PM CST this afternoon for LSZ140>146-148-150. Winter Weather Advisory until midnight CST tonight for LSZ142.