textproduct: Duluth

KEY MESSAGES

- Several rounds of thunderstorms develop this afternoon and evening, with numerous severe storms possible. All severe hazards are possible, including large to very large hail, damaging wind gusts, tornadoes, and locally heavy rainfall.

- Hot and humid conditions continue today away from Lake Superior, where high temperatures should be in the 80s with dew points in the 60s to low 70s. Northwest Wisconsin may need a Heat Advisory, but cloud cover and storms may mitigate this need.

- Additional, non-severe showers and storms on Thursday with cooling temperatures into the weekend.

- Dense fog on and near Lake Superior today and tonight. Visibility below one-quarter of a mile is expected on land and below 1 mile on Lake Superior.

DISCUSSION

Issued at 204 PM CDT Wed Jun 10 2026

The severe thunderstorm threat for this afternoon and evening and its associated threats will be the forecast challenge. Plentiful buoyancy with surface dewpoints in the mid to upper 60s, with a few dewpoint readings in the 70s, is in place. Effective deep layer shear of 30-40kts this afternoon is forecast to increase to 40-50 kts this evening as a strong mid level jet propagates across northeast Minnesota and northwest Wisconsin. This bouyancy-shear space is favorable for supercells, with storms becoming more organized and likely more intense late this afternoon and into the evening as the shear increases and low level buoyancy increases as well. All severe are hazards expected. This includes large to very large hail, potentially in excess of 2 inches, damaging winds in excess of 60 mph in northeast Minnesota and potentially in excess of 70 mph in northwest Wisconsin, and a few tornadoes. The greatest relative risk for tornadoes is across the I-35 corridor in northeast Minnesota and across most of northwest Wisconsin. With multiple rounds of thunderstorms expected until the cold front clears with multiple impulses moving across the area aloft, locally heavy rainfall and flash flooding will also need to be monitored.

The one limiting factor to storm organization and intensity thus far is backing winds in the mid levels, resulting in a bit less favorable hodographs for intense supercells. This mid level wind backing is depicted in forecast hodographs into the early evening. Another caveat to the hail threat in northeast Minnesota is upscale growth into a line along the cold front, which would limit the hail threat some, but make damaging winds the primary threat.

Looking ahead into the weekend and into next week, it will be cooler even away from Lake Superior with high temperatures in the upper 60s and lower 70s under cyclonic flow aloft. The overall airmass will also be drier. However, embedded impulses in the cyclonic flow means the forecast will not be precipitation free, with near daily chances for rain showers and thunderstorms in the afternoon through sunset across northeast Minnesota and northwest Wisconsin. Severe weather is not expected.

AVIATION /18Z TAFS THROUGH 18Z THURSDAY/

Issued at 1225 PM CDT Wed Jun 10 2026

Severe thunderstorms with large hail, damaging wind gusts in excess of 50kts, a few tornadoes and very heavy rainfall will develop across northwest Wisconsin and northeast Minnesota this afternoon and evening. Storms will increase in coverage after 20Z this afternoon. The threat will decrease after 05Z. LIFR conditions in very heavy rainfall is also expected. Dense fog near and on Lake Superior will also continue today and tonight.

MARINE /FOR NEARSHORE WATERS OF WESTERN LAKE SUPERIOR/

Issued at 902 AM CDT Wed Jun 10 2026

Dense fog with visibility below one mile will continue today through Thursday morning. A Marine Dense Fog Advisory is in effect.

Northeast winds continue today. Some afternoon gusts of 10-15 knots are possible at the head of the lake today, as well as 15-20 knots in parts of the North Shore this afternoon. Expect thunderstorms again this afternoon and evening. Some storms could become severe, with damaging winds (best chance closest to shore), large hail, and frequent lightning. Overnight into Thursday, winds becoming southwesterly with some stronger gusts approaching 20-25 knots at times, mainly in the Outer Apostles and portions of the North Shore. Hazardous conditions for small craft may be possible, but confidence was not high enough to issue with this update. Additional rain showers are possible on Thursday.

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

FIRE WEATHER

Issued at 206 PM CDT Wed Jun 10 2026

Scattered to numerous severe thunderstorms are expected this afternoon and evening, with all hazards possible including large to very hail, damaging wind gusts, and a few tornadoes. Good rainfall is expected, with widespread rainfall accumulations of 0.5-1.0"+ likely. Scattered rain showers and thunderstorms are forecast Thursday, and then slowly drying out into the weekend.

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

DLH WATCHES/WARNINGS/ADVISORIES

MN...None. WI...None. MARINE...Dense Fog Advisory until 7 AM CDT Thursday for LSZ121-140>148- 150.