textproduct: Duluth

KEY MESSAGES

- A line of strong thunderstorms lasts through about 10 PM today. A few severe storms in this time period could produce large hail and damaging wind gusts.

- Isolated non-severe thunderstorms are forecast Wednesday afternoon.

- Seasonal, dry conditions return for Thursday and Friday ahead of off-and-on thunderstorm chances for this weekend.

DISCUSSION

Issued at 1217 PM CDT Tue Aug 25 2026

A warm front is moving through the region mid-day today, bringing a few scattered showers and isolated thunderstorms to the tip of the Arrowhead and entering north-central Wisconsin. These storms are part of what is Round 1 and are not expected to be severe. Behind the warm front, atmospheric recovery will occur this afternoon and last into the early evening hours within the short-lived warm sector of a low pressure system centered over Manitoba, Minnesota, and Ontario. As daytime heating maximizes instability, isolated severe thunderstorms are possible beginning first in the far northern Minnesota Borderlands late this afternoon, with an onset time around 3 to 4 PM.

The hazard threats of Large Hail and damaging wind gusts will build southeastward early this evening towards the Twin Ports. By later this evening, closer to sunset, the severe threat moves into into northwest Wisconsin and the eastern Arrowhead. Severe storm chances are expected to taper shortly after sunset this evening with a cold frontal passage occurring tonight. Behind the front, lingering cold air advection showers will continue through the overnight hours, but these will only bring very localized and light rainfall to the Northland.

For Wednesday, a slight cool down is forecast and breezier post- frontal regime takes hold across the area. Expect gusty northwest winds sustained around 10 to 15 mph with gusts reaching 20 to 30 mph. The exception for the cool down will be the North Shore with those northwest winds downsloping and aiding in warmer temperatures for the immediate coastal areas.

The light and localized rain showers from the overnight hours will last into the Wednesday daytime period, actually increasing in coverage under daytime heating and instability. A few general thunderstorms are forecast Wednesday afternoon within this regime of numerous light and very localized rain showers. Severe weather is not anticipated on Wednesday.

Minimal weather concerns are expected for Thursday and Friday as passing high pressure brings a return to quiet and dry conditions across the region. It will feel fairly dry each afternoon with minimum relative humidity dropping to 35 to 45 percent range...winds generally remain around or less than 15 mph though so no fire weather conditions are forecast.

Looking ahead to the weekend, warm air advection sets up again Friday night into Saturday morning as a weak passing front and a low to mid-level ridge axis slides eastward into the northern Plains. This could be a time of a few scattered thunderstorms late Friday night into Saturday morning. Furthermore, strong thunderstorms cannot be ruled out later Saturday or at some point Sunday. A low pressure system in far northern Ontario and a reinforcing frontal passage forecast for Sunday will keep the pattern active, as convection over the Northern Plains may spill over and slowly decay into the Northland. Pending any increases in sky cover or lingering precipitation, Sunday could actually be somewhat warm into the mid-80s for locations south of US Hwy 2. Generally minimal weather concerns to start next week under seasonable temperatures and mainly dry conditions likely.

AVIATION /00Z TAFS THROUGH 00Z THURSDAY/

Issued at 646 PM CDT Tue Aug 25 2026

A cold front is moving through far eastern Minnesota and entering northwest Wisconsin early this evening. A wind shift is being observed with this cold frontal passage from southwest to west and then further northwest a few hours behind the front. Scattered severe thunderstorms remain possible through 03Z this evening for northwest Wisconsin and would primarily be concerned with Large Hail and wind gusts to 50 knots. Elsewhere in northeast Minnesota widely scattered rain showers will bring off-and-on light rainfall to terminals for much of this TAF period. An isolated non-severe thunderstorm can also not be ruled out through 03Z this evening and again Wednesday afternoon. Later tonight, incoming MVFR to maybe IFR ceilings are forecast at terminals through 13-16Z Wednesday. Gusty northwest winds will occur Wednesday.

MARINE /FOR NEARSHORE WATERS OF WESTERN LAKE SUPERIOR/

Issued at 1149 AM CDT Tue Aug 25 2026

A warm front is lifting across Western Lake Superior with a few non-severe storms. Stronger thunderstorms are possible this evening ahead of an approaching cold front. These storms may produce large hail and gale force wind gusts. Following the frontal passage tonight, winds will shift to the northwest and increase on Wednesday. Gusts of 20 to 25 knots are forecast, building waves across the South Shore. Scattered showers and a few thunderstorms will persist Wednesday before high pressure brings quieter marine conditions by Thursday.

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

FIRE WEATHER

Issued at 1156 AM CDT Tue Aug 25 2026

Minimum relative humidity values will generally remain above 45 percent today with southerly winds at 5 to 10 mph and gusts to 20 mph ahead of an approaching cold front. Showers and thunderstorms will cross the area this afternoon and evening. A few severe thunderstorms capable of Large Hail and damaging wind gusts to 60 mph are possible from 1500 to 1600 through 2100 to 2200 today. A wind shift to northwesterly will occur tonight behind a passing cold front. For Wednesday, minimum relative humidity values will again remain above 45 percent, but northwest winds will increase to 10 to 15 mph with gusts around 20 to 25 mph. Thursday sees decreasing northwest winds, but still sustained 5-8 mph gusting to 15 mph and minimum relative humidity of 35 to 45 percent. High pressure for later this week helps create even less wind for Friday, while remaining just as dry as Thursday.

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.