Marine Weather and Tide Forecast for Grand Marais, MN

DISCUSSION
Issued at 244 AM CDT Sun Oct 11 2026

Current Conditions/Today:

Another warm one on tap for today as the southerly flow persist for much of the region. While the warm air advection does not look to be as strong today with weaker winds expected we will still see those temperatures climbing into the 70s and 80s across the vast majority of the Northland. A cold front will move slowly from northwest to southeast across our region into tonight. The pacing of the front will be incredibly slow and near stationary at times. As the boundary sags south we will see rain chances slowly increase.
Sounding profiles still show a large amount of dry air that will need to be worked over before rain can reaches the surface. The best chances (20-40%) for rain at this time will likely stay confined to northern MN.

Monday:

The Northland finds itself within the baroclinic zone as southerly winds across the Midwest meet with the northerly winds out of the Canadian Prairies. A few impulses rounding the weak upper ridging aloft could instigate some light rain across northern MN through the first half of the day. Better synoptic forcing arrives in the latter half of the day and into the evening hours as a shortwave aloft pushes in from the west. Weak instability closer to a surface low moving across Southern MN into Central WI could produce a few rumbles of thunder Monday evening across NW WI. Overall, expecting light rain totals largely between 0.10-0.25" with rain exiting Tuesday morning.

Tuesday into the end of the work week:

High pressure builds into the region for Tuesday and starts to depart on Wednesday. Quiet weather conditions during this period with highs in the 50s and 60s and overnight lows in the 30s. Heading into Thursday and beyond there is a high degree of uncertainty among the 00Z suite of guidance. Cluster analysis that favors the EPS still wants to plot a cut off low over the desert southwest that would allow surface high pressure and ridging to dominate the Great Lakes Region. The clusters more aligned with the GEFS have a more pronounced upper level trough moving through the Central and Northern Plains that would suggest an active weather pattern for the end of the work week.
Leveraging the ECAIFS and the AIGFS may be the better option in the extended as they align fairly well and have been fairly consistent with their picture. It is slightly more agreement with the GEFS as the upper level low is less dominate over the desert southwest as a surface low moves across Manitoba and Ontario bringing a rainy period for the end of the week. For now, will stick with the NBM which continues to highlight PoPs of 30-50% through Friday.

AVIATION /12Z TAFS THROUGH 12Z MONDAY/
Issued at 626 AM CDT Sun Oct 11 2026

VFR conditions to start the forecast period with a strong low level exiting NW WI this morning. Low level wind shear over HYR will disperse later this morning. A very slow moving cold front will advance out of the northwest today with winds switching to out the north behind the boundary. Additionally, satellite this morning shows an expansive IFR/LIFR stratus deck behind the surface boundary slowly advancing across NW MN that will impact INL later this morning. Rain chances will also increase this afternoon with lingering chances across northern MN through the overnight period.

MARINE /FOR NEARSHORE WATERS OF WESTERN LAKE SUPERIOR/
Issued at 244 AM CDT Sun Oct 11 2026

Southwest winds gusting to around 20 knots this morning will weaken through the day. Winds will turn to out of the northeast tonight and increase in speeds through the early morning hours. Gales will be possible in this northeasterly flow with a Gale Watch in effect for the North Shore and most of the South Shore. High res guidance would suggest the areas most likely to see gales are from the Silver Bay down through the Twin Ports and around to the Outer Apostle islands.
Gales are likely to diminish Monday afternoon but wind speeds and wave heights would still remain hazardous for small vessels through Tuesday morning.

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

FIRE WEATHER
Issued at 244 AM CDT Sun Oct 11 2026

Another day of summer like temperatures across the region. Not nearly as windy as yesterday with wind gusts expected to be around 20-25 mph. Yesterday did see some overachieving Min RHs with some isolated spots dropping to around 25% in the Brainerd Lake region.
Can't fully rule out some isolated spots achieving this again with the abundance of sun but this would largely be isolated to NW WI. A slow moving cold front will be advancing out of the northwest at an incredibly slow pace with winds slowly turning to out of the north behind this boundary. Some isolated showers will be possible across northern MN this evening and overnight. More widespread rain chances will arrive late Monday with totals largely between 0.10-0.25"

See the Fire Weather Forecast product for a more thorough breakdown of fire weather conditions.

DLH WATCHES/WARNINGS/ADVISORIES
MN...None.
WI...None.
MARINE...Small Craft Advisory until 7 AM CDT this morning for LSZ121- 140-145>148-150.
Gale Watch from late tonight through Monday evening for LSZ140>147-150.