textproduct: Duluth

KEY MESSAGES

- Patchy fog, locally dense, continues early this morning. This may lead to travel impacts for the Friday morning commute, with localized areas seeing visibility as low as one quarter of a mile.

- Scattered showers with isolated non-severe thunderstorms will be possible this afternoon and evening, especially in the Arrowhead. A strong storm or two may occur today, capable of producing small hail and gusty winds to 40 mph.

- Pleasant weather conditions are forecast this weekend with comfortable high temps in the 70s and abundant sunshine. Additional shower and thunderstorm chances arrive early next week on Monday night into Tuesday.

DISCUSSION

Issued at 335 AM CDT Fri Aug 21 2026

A shortwave is currently propagating through the area early this morning, with the scattered and thunderstorms that impacted the CWA yesterday evening now moving downstream. In the wake of this precip, patchy fog and low stratus have developed early this morning. Localized dense fog is also occurring early this morning, with visibility as low as one quarter of a mile. This fog is expected to linger until shortly after sunrise, leading to travel impacts for the Friday morning commute. Opting against issuing a Dense Fog Advisory at this time, as dense fog has been fairly sporadic and intermittent.

Today will see more benign conditions compared to yesterday as the sfc low continues to move east and the CWA sits under a pattern of northwest flow aloft. A second 500mb shortwave is expected to propagate into the Upper Great Lakes region this afternoon and evening, which will bring a chance for scattered showers into the area. Isolated thunderstorms will also be possible, as MLCAPE this afternoon and evening increases to 200-1000 J/kg and modest 0-6km bulk shear of 25-30 knots occurs. This instability likely won't be enough to generate severe storms, as hi-res model soundings show a fairly skinny CAPE profile. However, a strong storm capable of producing small hail and gusty winds to 40 mph will still certainly be possible today. Expect showers and storms to come to an end by tonight as the shortwave continues to propagate downstream.

Pleasant summer weather is anticipated this weekend as high pressure builds into the region and northwest flow keeps high temps in the 70s with comfortable humidity. While min RH does trend on the drier side on Sunday in the 30 to 40% range, fire weather concerns will be mitigated by the light and variable winds expected on Sunday. Enjoy the weather this weekend!

This dry and pleasant weather continues through much of the day Monday, albeit with slightly warmer temps as southerly flow provides WAA. Cloud cover will be increasing through the day on Monday as vertically-stacked low pressure propagates from the Canadian Prairies into the Great Lakes region. This low pressure will bring additional chances for showers and thunderstorms on Monday night through Tuesday. On Wednesday, additional shower activity will be possible in the post-cold front environment. The latter half of next week is favored to see a return of high pressure and pleasant summer high temps in the mid 70s to around 80 degrees.

AVIATION /06Z TAFS THROUGH 06Z SATURDAY/

Issued at 1231 AM CDT Fri Aug 21 2026

Isolated thunderstorms in portions of northwest WI early this morning will be coming to an end over the next couple hours. Areas of fog are developing behind this rainfall, which will be impacting all terminals early this morning. Expect areas of IFR to LIFR conditions to start the day, improving to VFR later this morning into the afternoon. Scattered rain showers will be possible late in the afternoon into the evening, although conditions will likely remain VFR.

MARINE /FOR NEARSHORE WATERS OF WESTERN LAKE SUPERIOR/

Issued at 335 AM CDT Fri Aug 21 2026

Patchy fog is expected early this morning, clearing shortly after sunrise. An isolated shower or thunderstorm will be possible this evening, especially along the North Shore. While severe storms are not expected, small hail may occur under a strong storm or two. Light and variable winds today become northwest tonight into Saturday with high pressure moving into the area. These northwest winds on Saturday preceding the high pressure will be breezy in the afternoon, gusting 15-20 knots. Light and variable winds return on Sunday, with gusts forecast to remain under 10 knots.

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

FIRE WEATHER

Issued at 335 AM CDT Fri Aug 21 2026

Northwest winds are expected today through Saturday following the cold frontal passage occurring early this morning. High temps today will be in the 70s for most with elevated min RH values of 45% or higher. A secondary cold front arriving late this afternoon into the evening will bring a chance for scattered showers with isolated thunderstorms. While severe storms are not expected, strong storms capable of producing small hail and gusty, erratic wind gusts to 40 mph will be possible, especially in the Arrowhead.

High pressure builds this weekend, with Sunday currently expected to be the driest day. Min RH on Sunday will be as low as 35%, although light and variable winds limit fire weather concerns. Additional showers and thunderstorms are forecast to arrive Monday night into Tuesday. Moderately dry min RH as low as 35% does linger on Monday in the Arrowhead and northwest Wisconsin, although cloud cover will be increasing through the day.

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

DLH WATCHES/WARNINGS/ADVISORIES

MN...None. WI...None. MARINE...None.