textproduct: Duluth

KEY MESSAGES

- Scattered showers and thunderstorms continue across the area this morning. After a break in activity, additional showers and storms arrive this afternoon and evening. Several rounds of convection are possible through Tuesday.

- Marginal risk of severe storms late today into Tuesday morning. There remains potential for redevelopment of strong to severe storms Tuesday afternoon as well.

- Strong northwest winds are expected Wednesday, both inland and over the waters of western Lake Superior. Wind gusts to 35 mph are possible over the Arrowhead, with gale- force wind gusts over western Lake Superior this week.

UPDATE

Issued at 330 AM CDT Mon Sep 7 2026

An area of showers and thunderstorms is moving eastward this morning, now over the Arrowhead stretching southward to the South Shore. Strong to severe storms are not expected given weak shear profiles, but a wind gust to 20-25 mph and brief heavy rainfall is possible. This activity is being driven by a weak shortwave rounding the ridge axis that extends northward through the Upper Mississippi River Valley that is pushing eastward toward the Great Lakes. As that shortwave pulls to the east, a break in rainfall is expected this morning, with cloudy skies persisting.

As noted in the previous discussion below, we will remain in the warm sector today, ahead of an approaching cold front associated with a low moving into central Canada. This might result in ongoing scattered showers, but do not expect continuous rainfall today. The next round of organized showers and storms arrives late this afternoon into the early evening, from the west. This would be the first in a several of waves of storms that will move through the area through Tuesday morning. The evening activity might pose a severe threat with shear values of 40kts. However, instabilities are weak, which could limit the overall severe threat. Better lapse rates arrive early Tuesday morning, along with weak CAPE values and bulk shear of 50kts. Could see a strengthening of storms with large hail and damaging winds possible late tonight into early Tuesday.

As the cold front moves through the area Tuesday afternoon, a few storms are possible mainly over the Arrowhead. If the storms develop in the wake of widespread morning storms, they could be strong to severe as well. Northwesterly flow will increase behind the cold front on Wednesday, resulting in gusty winds over the area. There is about a 40% chance of wind gusts over 40mph over the Arrowhead and parts of the South Shore, and wind advisories might be needed.

DISCUSSION

Issued at 231 PM CDT Sun Sep 6 2026

Tonight/Labor Day.

Overnight, the ridge axis shifts further east towards the Great Lakes as a shortwave advances out of the Northern Plains. Moisture profiles begin to saturate leading to a slight increase in PoPs for the overnight and early morning hours across northern MN. A few thunderstorms will be possible as well, but the environment is lacking deep layer shear which will keep storms on the tame side. Through the remainder of the holiday the Northland will find itself in the warm sector of an approaching system in the Northern Rockies. The continued warm air advection and isentropic forcing may lead to off and on rain chances through the day with mostly cloudy skies. Temperatures will be in the 70s with a few low 80s possible. Additionally, the southerly winds will see our dew points climb into the upper 60s by the afternoon.

Late Labor Day into Tuesday:

Large scale ascent is expected to increase late Labor Day and through Tuesday morning. An upper level trough over the Canadian Prairies pushes the ridge completely out of the Northland opening the door for southwesterly flow to stream back into the region. One of the unique aspects of this incoming set up is the high PWATs that the system will have access to. The IVT plots would suggest contributions from both the the Gulf and Hurricane Marie. Climatology puts the incoming PWATs near the max of climatology. Despite this wealth of moisture, most of the guidance keeps QPF fairly moderated. EFI is mainly honing in on areas north of the International Border as being the hotpots for heavy rainfall, likely coinciding with the warm frontal boundary. While we may not be the recipients of the highest rain totals we should still see our fair share with current guidance suggesting around an 1" for most of MN with lower amounts across the Arrowhead and NW WI.

Severe chances start to increase late Monday as well with an upper level jet nudging in from the southwest. Instability may be limited with high PWATs and lack of mid level lapse rates. With these meager ingredients in play the SPC has out western counties outlined in a marginal risk (threat level 1 out of 5). Primary hazard would likely be hail the size of quarters with damaging winds being a secondary threat. Storm activity could be persistent into Tuesday as a low level jet strengthens across the Midwest.

Tuesday will see ongoing showers and storms through the morning. The upper level low over the Canadian Prairies will strengthen with a noticeable dry slot sweeping in behind the cold front set to move through the region. Depending on how quickly the front advances east the region we could have some lingering severe storm threat into NW WI in the afternoon.

Wed - Fri:

On Wednesday the upper level low spins into the Hudson Bay with persistent cyclonic flow aloft over the region. Low level moisture still looks favorable with mid and upper level moisture questionable at the moment. The pattern looks pretty similar to the ones we get with isolated showers and more widespread drizzle. Overall, expecting a cloudy day with much cooler temperatures. Highs may not climb out of the 70s in northern MN with NW WI in the mid and low 70s. Thursday looks to be the quietest weather day in the upcoming week with surface high pressure gliding across the Midwest. Rain chances look to return Friday as another front cross through the Northland.

AVIATION /06Z TAFS THROUGH 06Z TUESDAY/

Issued at 115 AM CDT Mon Sep 7 2026

Numerous rain showers and isolated general thunderstorms are moving across northeast Minnesota tonight. Impacts from this activity will be brief heavy downpours and MVFR vis reductions. Lightning and a wind gust to 20kts cannot be ruled out with general thunderstorms.

Outside of convection, southeast winds at 10kts at DLH will allow for occasional LIFR cigs, due to uplift from the lake. Winds will generally be less than 8kts at other terminals. A lowering to MVFR cigs are possible at other terminals, other than HYR, toward sunrise. Winds will increase from the southeast through the day Monday, with gusts to 20-25kts. Additional showers and storms are possible, especially by mid to late afternoon.

MARINE /FOR NEARSHORE WATERS OF WESTERN LAKE SUPERIOR/

Issued at 330 AM CDT Mon Sep 7 2026

Easterly winds continue across Lake Superior around 5 to 10 kts this morning. Winds will increase through the day, with a few gusts to 25kts possible along the North Shore this evening. Winds will slowly turn to out of the south this evening, and increase further along the North Shore. By early Tuesday morning, widespread wind gusts of 25kts are possible, with gales possible from Grand Portage to Grand Marais. The Gale threat diminishes Tuesday afternoon but will likely still need a Small Craft Advisory. Widespread Gales across all the Near Shore waters and possible the South Shore continue to look likely for Wednesday. Additionally, showers and thunderstorms will be possible late Monday through Tuesday evening.

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

FIRE WEATHER

Issued at 330 AM CDT Mon Sep 7 2026

Low fire weather concerns through most of the forecast. Active weather pattern with high dew points back across the region through midweek. Additional rain totals for today through Tuesday night range from around an 1" across northern MN with less amounts expected south of US-2 eastward into NW WI. The heaviest rainfall is expected tonight into Tuesday morning. Additionally, there will be the risk of strong to severe storms tonight into Tuesday morning, with an isolated risk of a strong to severe storm again Tuesday afternoon.

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 4 AM Tuesday to 7 AM CDT Wednesday for LSZ121-142>148-150. Small Craft Advisory from 7 PM this evening to 4 AM CDT Tuesday for LSZ140. Gale Watch from late tonight through Tuesday afternoon for LSZ140. Small Craft Advisory from 7 PM this evening to 7 AM CDT Wednesday for LSZ141.