Marine Weather and Tide Forecast for Duluth, MN

DISCUSSION
Issued at 1120 AM CST Thu Feb 12 2026

High pressure currently centered over the Northland is providing sunny skies and quiet conditions today. Temperatures will begin a trend today that lasts into early next week of being in the mid 30s to low 40s for daytime highs. These very warm temperatures and possible melting off the current snowpack under a low-level stable layer each night is forecast to bring fog.
The most likely area tonight is over northern Minnesota and the stateline counties of far western Wisconsin. Similar conditions are expected again Saturday morning, but may expand even further eastward into the rest of northwest Wisconsin.

A weak clipper system moves through far northern Ontario Sunday night. This clipper is likely to lack any notable moisture to keep only around a 10 percent chance of very light snowfall for the Arrowhead and Borderlands Sunday night into Monday.

Our primary focus is on a potent Colorado Low expected to emerge from the Rockies and track toward the Great Lakes by the middle of next week. Warm air and deep moisture will surge northward ahead of this system starting Tuesday morning. Initial precipitation would likely begin as a messy mix of combination of rain, freezing rain and snow Tuesday PM before transitioning to a bit colder airmass favoring more snowfall precip type at some point Wednesday when as the main low pressure center moves through to the south. Because the exact track of the low is still being determined, the transition line between rain and heavy snow remains uncertain. However, the high moisture content of this system suggests the potential for plowable snow and travel disruptions across the Northland Tuesday night through Wednesday.

If any snowfall is allowed to accumulate mid next week, the setup shown in deterministic and ensemble global guidance supports the forecast of a more wet snowfall Tuesday PM into Wednesday. The snow to liquid ratio is very likely to be much lower (warm residual airmass already in place and being advected in still and a high liquid content available from this system as just two environmental indicators) with any snowfall that does fall mid- next week as the Colorado Low moves through, especially compared to the clipper systems we have observed mainly this last month. Many of those clippers have had observed snow to liquid ratios of 20-30:1 (as in if 20 inches of snow had fallen then that would equal out to 1 inch of liquid equivalent precipitation) at the NWS Duluth Forecast Office. It is too early to provide exact values for the system next week, but expect a more general range of snow to liquid ratios of 5-12:1 if any snowfall is observed. That lower-end being favored more towards the onset of precipitation and the higher-end being favored towards the end of the system.

AVIATION /00Z TAFS THROUGH 00Z SATURDAY/
Issued at 527 PM CST Thu Feb 12 2026

VFR conditions for awhile, but patchy fog / low stratus is expected between 07-18Z. May see LIFR conditions especially at KINL and KBRD though possibly elsewhere too. The Red River Valley is presently siting in this soup that should advect east overnight. Models really are hitting the low conditions hard over northeast Minnesota. Less confidence the further east you go including at KDLH where some sunrise surprise clouds/fog may appear. NW winds will keep the Duluth area a bit more mixy in the morning with gusts to 25 knots possible as a cold front follows a warm front in the morning.

MARINE /FOR NEARSHORE WATERS OF WESTERN LAKE SUPERIOR/
Issued at 1040 AM CST Thu Feb 12 2026

Expect benign conditions across the nearshore waters of Western Lake Superior for the next 48 hours as high pressure moves through. Winds will shift southwesterly at 10 to 15 knots tonight with some gusts approaching 20 knots near Grand Portage. Waves will remain 1 foot or less through Friday night.

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

DLH WATCHES/WARNINGS/ADVISORIES
MN...None.
WI...None.
MARINE...None.