textproduct: Duluth

KEY MESSAGES

- Next best chance of rain Thursday afternoon and evening overnight into Friday morning. Isolated to scattered severe storms capable of producing all hazards could affect areas from the Brainerd Lakes to the I-35 corridor to Washburn County. Damaging winds and large hail are the primary threats with a secondary tornado threat.

- Slightly above normal temperatures persist through the week and into the weekend, with another round of scattered showers and thunderstorms, possibly severe, late Saturday into Sunday.

- Another round of rain could affect portions of the Northland early next week.

DISCUSSION

Issued at 146 PM CDT Wed Sep 2 2026

A departing low pressure system pulling east across central Ontario and Quebec continues to help spur some cloud development this afternoon, but otherwise fairly calm weather is expected through this evening.

Somewhat dissonant to our current calm conditions should be the weather expected for the end of the week. Within a persistent omega block, upper level shortwave troughing is expected to dig into a broad ridge. This should help spur the development of a weak surface low pressure system over the Dakotas through the day Thursday, tying into a preceding warm front stretching from north central MN to the eastern Great Lakes. As a warm, moist surface airmass advects northward into this frontal boundary, it should meet a plume of steep mid-level lapse rates thanks to a EML coming out of the Rockies. This should make for a conditionally unstable environment primed to support severe storms if initial development can overcome capping. Storm development will likely be tied to passing upper level vortices, which could provide enough lift to develop storms through that aforementioned capping. The first disturbance looks to move through Thursday morning, but most guidance keeps that activity to our south. Then, we'll have to watch for potential storm development along the front as it slowly lifts north across the southern border of our CWA through the day and the environment recovers from any morning convection. This could align with the next synoptic disturbances through the afternoon and evening. A couple different rounds of potentially severe storms could move through along this front from mid Thursday afternoon through late evening but confidence on exact storm development location is low. Any severe storms that do develop would be capable of producing damaging winds and large hail. A tornado or two could be possible within the strongest storms as well.

Overnight, a loss of instability should help diminish severe storm potential. Into Friday morning, areas of rain and non-severe thunderstorms could continue across the Arrowhead and into NW WI, as the surface low pressure system pushes east across the CWA. As better upper level ridging moves into the area, precipitation chances should diminish through the day Friday, though high dewpoints will make for a continued sticky airmass.

Saturday should be largely dominated by high pressure allowing for ongoing warmth and moisture advection. This should set the stage for additional ridge running upper level disturbances to take advantage of a primed environment and develop additional showers and thunderstorms at some point between Saturday evening to Sunday night. Exact track, location, and intensity are uncertain.

Early next week, all global models are picking up a signal for a surface low pressure to push out of the Northern Rockies and into the Canadian Plains as the omega block breaks down. This could bring another round of rain and thunderstorms to our area.

As we stay largely under the influence of broad upper level ridging through the forecast period, temperatures are expected to be slightly above normal with dewpoints lingering in the 60s to low 70s.

AVIATION /18Z TAFS THROUGH 18Z THURSDAY/

Issued at 1226 PM CDT Wed Sep 2 2026

Largely VFR conditions are expected through the TAF period. Some light fog is possible at HIB overnight. Gusty northeast to east winds pick up through the morning tomorrow.

MARINE /FOR NEARSHORE WATERS OF WESTERN LAKE SUPERIOR/

Issued at 146 PM CDT Wed Sep 2 2026

A light lake breeze is expected for the rest of the day across Western Lake Superior. Into Thursday, winds become northeasterly and strengthen. Expect afternoon and early evening northeast winds of 10- 20 knots with gusts of 20-30 knots. A Small Craft Advisory has been issued for the head of the lake near the Twin Ports and portions of the Outer Apostle Islands to Saxon Harbor. Northeast winds weaken but don't disappear overnight into Friday morning, and are expected to restrengthen during the day Friday, especially for the Twin Ports and North Shore. Another Small Craft Advisory will likely be needed Friday. Some scattered showers and thunderstorms could affect portions of western Lake Superior Thursday night into Friday morning, but no severe storms are expected.

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

FIRE WEATHER

Issued at 146 PM CDT Wed Sep 2 2026

After a dry-ish day today, fairly moist conditions are expected for the second half of the week and into the holiday weekend. Afternoon minimum RH should stay above 50% Thursday through Sunday. Some gusty east to northeast winds are possible Thursday and Friday, especially closer to Lake Superior. Areas of showers and thunderstorms are expected to develop through the day Thursday and continue into Friday morning. There is a chance for isolated to scattered severe thunderstorms late Thursday afternoon through early Friday morning, most likely from the Brainerd Lakes to I-35 corridor to Spooner and south. Damaging winds and large hail are the primary threats with a secondary tornado threat.

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 noon Thursday to 1 AM CDT Friday for LSZ144-145. Small Craft Advisory from 3 PM to 10 PM CDT Thursday for LSZ148-150.