textproduct: Duluth

KEY MESSAGES

- Storm chances return this evening into early Tuesday morning. There is a slight risk (level 2 out of 5) for portions of northern MN. Damaging winds and large hail are the main threats. Tornado threat is low

- Mostly dry with seasonable temps for mid week into the weekend.

DISCUSSION

Issued at 315 PM CDT Mon Aug 3 2026

This Afternoon and Tonight:

The Northland is in a bit of a lull, storm wise, this afternoon. Widespread cloud cover has kept temperatures in the 70s over the Arrowhead while elsewhere, temps are in the low to mid 80s. A stalled front is sitting just to our west, with more widespread showers and a couple storms remaining back over the Red River Valley. Through the rest of the afternoon, south winds will continue to increase, bringing warm air and moisture northward. This morning's INL sounding showed a substantial inversion (and a cap around 800mb). If there are enough breaks in the clouds to build more instability, an area of 50-60kts of bulk shear is nosing into the Lake of the Woods and Kooch county. If a storm can develop this afternoon, it could be strong to severe. If it can become surface based, there is a non-zero chance of a tornado. But, forcing looks weak, as we wait for the next shortwave to kick the front eastward.

The main impact period will be this evening into early Tuesday morning, as a broken line of storms along an approaching cold front strengthens to our west and moves into northeast MN. The airmass ahead of the front will be characterized by 1000-1500 J/kg (MUCAPE), 40-60kt of bulk shear right along the front, and lapse rates of at least 7C/km. Storms could be strong to severe, with large hail and damaging winds possible. Cannot rule out a tornado within the broken line.

Storms will continue to move across the region through the overnight period with the severe risk fading in the early morning hours as instability and wind features weaken. Scattered showers could linger across portions of northwest WI and the tip of the Arrowhead through mid morning tomorrow.

Mid week:

Surface high pressure moves over the region for for mid week as the upper level pattern supports broad troughing across much of the northern CONUS. Drier air will likely keep conditions dry despite the troughing aloft. A stronger shortwave arrives this weekend, bringing better rain chances. Temperatures stay in the 70s through Wednesday, then slowly climb through the end of the work week.

AVIATION /00Z TAFS THROUGH 00Z WEDNESDAY/

Issued at 626 PM CDT Mon Aug 3 2026

As a cold front advances from our west, thunderstorms will move west to east across the Northland this evening into Tuesday morning. Some storms will be strong to severe. Outside of convective winds, gusts to 25kts are possible, with winds shifting to the west and northwest early Tuesday morning behind the front.

With a strengthening LLJ, there could be a period of LLWS before a broken line of storms arrives. Best potential for this is at DLH and HYR. DLH may even see some fog build in behind the front, so popped in a prob30 for that.

MARINE /FOR NEARSHORE WATERS OF WESTERN LAKE SUPERIOR/

Issued at 315 PM CDT Mon Aug 3 2026

Light and variable winds continue through early afternoon before marine winds increase from the east to northeast ahead of an approaching front. With the cold front, expect showers and storms to enter western Lake Superior around midnight, with a wind shift to the southwest. Small Craft Advisories have been issued for wind gusts up to 25-30 kts. This activity will clear to the east Tuesday morning. Westerly winds will filter in behind the front with additional Small Craft Advisories likely being needed.

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

FIRE WEATHER

Issued at 315 PM CDT Mon Aug 3 2026

Moisture is increasing ahead of an approaching cold front, with RHs remaining in the 60-70% range across the Arrowhead this afternoon. With afternoon temps still warming and some possible breaks in the clouds, mixing is possible into mid to late afternoon, with min RHs falling below 50%. Elsewhere, less cloud cover has allowed warmer temps and RHs to fall into the upper 40s. Winds are increasing from the south, with gusts to 20-25mph already across the west. Expect stronger winds to spread into the Arrowhead through the afternoon.

Strong to severe storms are expected to enter from the west this evening as a cold front moves through. Storm strength is expected to wane in the early morning hours with activity exiting the region Tuesday morning. Winds will become westerly to northwesterly late tonight and early Tuesday morning. Behind the front, drier air will move into the region. For Tuesday, min RHs fall to around 40% with west winds at 10 to 15mph. Min RHs will be in the mid to upper 30% Wednesday with weaker winds.

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 from 10 PM this evening to 8 AM CDT Tuesday for LSZ121-144>148-150. Small Craft Advisory from 1 AM to 8 AM CDT Tuesday for LSZ140.