textproduct: Duluth

KEY MESSAGES

- Strong southwest winds continue this afternoon into Sunday with elevated fire weather concerns today.

- Gales are expected to occur over portions of western Lake Superior this evening into Sunday morning with elevated wave heights. Mariners should use extreme caution, especially around the Apostle Islands and along the North Shore above Silver Bay.

- Minimal chances for rain through the forecast period with a gradual warming trend early this upcoming week.

DISCUSSION

Issued at 222 PM CDT Sat Oct 17 2026

Clear skies have been occurring this afternoon as high pressure centered over the central CONUS dominates the pattern across the Midwest. A strong pressure gradient is located over the CWA today, resulting from the aforementioned high pressure in the mid Mississippi River Valley and an area of low pressure undergoing cyclogenesis in the lee of the Canadian Rockies in northern Alberta and Saskatchewan. This strong pressure gradient has been causing breezy southwest winds, which are forecast to continue through much of Sunday. These strong winds are leading to elevated fire weather concerns today. One thing of note is that mixing will be somewhat limited this afternoon as a strong warm nose at 850mb occurs, keeping min RH in the upper 20% to low 30% range for most locations.

The WAA resulting from the strong southwest flow will cause low temps tonight to be significant warmer compared to last night, in some portions of the CWA as much as 10-15 degrees warmer. Cloud cover is expected to increase tonight as a cold front associated with the developing low pressure in Canada arrives to the Upper Midwest. Precipitation is not expected with this cold frontal passage on Sunday. In addition to an increase in cloud cover, this cold frontal passage is forecast to result in easing winds on Sunday as high pressure builds into the CWA behind the front.

This pattern of high pressure is anticipated to be the dominant pattern for much of this upcoming week, with very little to no chances for precipitation for the next several days as an omega block likely develops. Temperatures will be seeing a gradual warming trend early this week, with highs increasing from the upper 50s to low 60s on Monday to the low to mid 60s for most by Wednesday. Global models are generally in agreement that a shortwave trough will ride over the omega block through northern Ontario on Wednesday, which could bring increased cloud cover to the CWA. However, precipitation is currently forecast to remain north of the border.

The question of when our next best chance for precipitation will be is highly uncertain. Global models and ensembles suggest the potential for this omega block to break down on Friday into next weekend, with a cutoff low over southern California and the Great Basin propagating northeast towards the Midwest as a shortwave moves through the Pacific Northwest and Northern Rockies. However, confidence in this timing remains very low given how far out in the forecast period this is and the tendency for omega blocks to be slow to break down.

AVIATION /00Z TAFS THROUGH 00Z MONDAY/

Issued at 631 PM CDT Sat Oct 17 2026

VFR conditions are expected through the period. Breezy southwest winds will continue through tonight and most of Sunday. As a low-level jet develops this evening and overnight, which should produce LLWS at all terminals. This LLWS eases on Sunday morning as the nocturnal LLJ dissipates. Winds diminish during the afternon hours on Sunday.

MARINE /FOR NEARSHORE WATERS OF WESTERN LAKE SUPERIOR/

Issued at 222 PM CDT Sat Oct 17 2026

A strong pressure gradient across western Lake Superior has been producing wind gusts of 25-30 knots, with the occasional gale occurring around the outer Apostle Islands and near Grand Portage. A Small Craft Advisory remains in effect for all nearshore waters through this afternoon and evening and into Sunday. For tonight, a Gale Watch has been issued from Port Wing to Sand Island, in the outer Apostle Islands, and from Grand Marais to Grand Portage. This is expected to be upgraded to a Gale Warning later this afternoon, which will continue through Sunday morning. Additionally, expect wave heights to be highest along the North Shore measuring at 6 to 9 ft for today and increasing to 8-11 ft and occasionally upwards of 16 ft tonight.

Winds will gradually be easing on Sunday into Sunday night as high pressure begins to dominate the pattern for early next week. Expect waves to also begin subsiding following the easing winds.

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

FIRE WEATHER

Issued at 222 PM CDT Sat Oct 17 2026

Strong southwest winds have been occurring today with gusts up to 30 mph under clear skies. An inversion has been in place across the region today due to warm air aloft in the low-levels. This has resulted in mixing heights being on the lower end, especially considering the abundant sunshine and warmer temps. RH has been slightly more elevated today as afternoon mixing has been limited, although the WI pine barrens have been a notable exception to this with dry min RH in the low to mid 20% range occurring. Expect these strong southwest winds to persist through tonight into Sunday. Winds will be easing on Sunday evening following the passage of a dry cold front, which is forecast to shift winds to the northwest. An increase in cloud cover ahead of the dry cold front and increasing dewpoint temperatures on Sunday will likely keep RH trending similar to a bit higher tomorrow.

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 PM CDT Sunday for LSZ121-141>145- 147-148. Small Craft Advisory until 10 PM CDT this evening for LSZ140- 146-150. Gale Warning from 10 PM this evening to 1 PM CDT Sunday for LSZ140-146-150.