textproduct: Duluth

KEY MESSAGES

- Isolated severe thunderstorms are possible this afternoon and evening across the far northern Arrowhead, bringing threats of hail up to half-dollar size and wind gusts up to 60 mph.

- A strong lake breeze on Wednesday will bring much cooler temperatures near Lake Superior while hot conditions persist inland.

- Hot and dry conditions will lead to periods of near-critical fire weather concerns across parts of the region later this week.

DISCUSSION

Issued at 132 PM CDT Tue May 26 2026

For the rest of the day, warm southerly flow will meet a slowly advancing cold front moving from north to south across the Northland. An inversion currently in place is expected to mix out later this afternoon, allowing a seasonably moist air mass to establish sufficient instability with around 1000 J/kg of CAPE. A small mesoscale convective vortex that developed earlier today is migrating northward, providing the necessary forcing boost to spark isolated to scattered thunderstorms this afternoon and evening. Although deep-layer wind shear is quite weak, a few pulse-style storms could become strong to severe, capable of producing penny to half-dollar size hail and wind gusts of 40 to 60 mph, primarily south of the US Highway 2 corridor. Highs will top out in the 80s inland but remain cooler north of the front. Storms will fade tonight with a loss of heating, leaving partly cloudy skies and lows in the upper 40s to mid 50s.

On Wednesday, a Canadian high pressure pushes toward the Great Lakes, turning winds easterly to northeasterly across the entire area. A tighter pressure gradient will generate gusty northeast winds up to 25 mph over western Lake Superior. Waves will increase along the shoreline as a result, increasing the risk for rip currents in the afternoon for swimmers. This will also bring a prominent lake breeze inland, causing a sharp temperature contrast which will keep areas near the big lake chilly in the 60s and lower 70s, while inland locations remain hot in the 80s. By Thursday, the surface high centers itself over the region, maintaining dry and sunny conditions. The persistent lake breeze will continue to suppress daytime highs into the 60s along the shorelines, while inland locations will have mid 70s to low 80s under clear skies.

The weather pattern shifts again on Friday as the surface high pressure system weakens and drifts southward, allowing winds to turn back to the south. Our region will remain positioned under a large, stalled upper-level ridge that dominates the central Plains and Canadian Prairies. This block ensures that unseasonably warm and dry conditions linger across the Northland. Friday looks to be exceptionally hot, with inland high temperatures surging back into the upper 80s and lower 90s, potentially approaching/breaking daily records. A weak passing upper-level disturbance could touch off a few isolated showers or thunderstorms Friday evening, but chances remain low near twenty percent, and most locations will stay dry.

Over the weekend and into next Monday, the stalled out ridge aloft remains firmly in place, extending the period of dry and warm weather. At the surface, another strong area of high pressure will drift southward from Hudson Bay into Ontario on Saturday and Sunday. The resulting pressure gradient will reintroduce a steady northeast wind, triggering another robust lake breeze. Temperatures will once again split, with locations along Lake Superior holding in the upper 60s to mid 70s, while inland areas stay hot in the low to mid 80s. Aside from an isolated afternoon storm threat in northwest Wisconsin on Saturday, the multi-day stretch will feature mostly clear skies and stable conditions through the start of the next work week.

AVIATION /06Z TAFS THROUGH 06Z THURSDAY/

Issued at 1238 AM CDT Wed May 27 2026

Scattered showers occurring in the Borderlands near KINL have occasionally been producing lightning. The expectation is that thunderstorms will be coming to an end within the next hour. Patchy MVFR to IFR fog will potentially develop later this morning, especially around terminals that saw rainfall yesterday afternoon and evening. Any fog that forms will dissipate shortly after sunrise, giving way to VFR conditions and gusty easterly winds.

MARINE /FOR NEARSHORE WATERS OF WESTERN LAKE SUPERIOR/

Issued at 132 PM CDT Tue May 26 2026

For western Lake Superior, east to northeast winds will gradually strengthen for the rest of today to 5 to 12 knots, with gusts up to 15 to 18 knots in the southwest arm. Waves will remain 2 feet or less. On Wednesday, a tight pressure gradient will increase northeast winds to 10 to 18 knots with gusts peaking between 15 and 25 knots. Waves will build to 2 to 4 feet near the Twin Ports and from Oak Point to Saxon Harbor, creating hazardous conditions for small craft. Northeast winds will weaken on Thursday but will remain up to 15 kts at the head of Lake Superior.

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

FIRE WEATHER

Issued at 132 PM CDT Tue May 26 2026 Dry, near-critical relative humidity values between 20 and 30 percent are forecast this afternoon for areas extending from near Walker to Ely. Winds will be light and variable at 5 to 10 mph north of a sagging frontal boundary, and southerly at 5 to 10 mph south of it. On Wednesday and Thursday, winds turn northeast, bringing a cool lake breeze and higher humidities to the shorelines while inland relative humidity drops to 25 to 35 percent. Warmer temperatures, lower humidity, and southerly winds return on Friday. Due to a stalled ridge and an ongoing lack of wetting rain, near-critical fire weather conditions are expected daily for different portions of the Northland throughout the week.

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

CLIMATE

Issued at 132 PM CDT Tue May 26 2026

Friday, May 29: Forecast Record -------- ------ KDLH: 84 ........ 87 in 1986 KHIB: 90 ........ 88 in 1999 and 2006 KINL: 91 ........ 92 in 1999 and 2006

DLH WATCHES/WARNINGS/ADVISORIES

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