textproduct: Duluth

KEY MESSAGES

- Next best chance of rain is Thursday afternoon and evening 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 top 70 mph and large hail to ping pong ball size 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.

UPDATE

Issued at 1258 AM CDT Thu Sep 3 2026

A stationary boundary was draped across southern Minnesota into central Wisconsin early this morning. Isentropic lift over the front led to the development of isolated showers and thunderstorms across east-central Minnesota earlier this evening, but that activity has quickly fizzled out. CAMs continue to advertise an area of showers and thunderstorms moving out of the Dakotas later this morning then across the Northland through midday. The HRRR continues to be an outlier with this area of showers and thunderstorms not arriving until midday and lingering into mid-afternoon. Current radar across northern South Dakota shows some isolated thunderstorm development. Most CAMs have more robust activity at this time which then grows upscale as it moves to the east while the HRRR loses this convection over the next few hours with additional development not occurring until closer to daybreak across southeastern South Dakota and southern Minnesota.

If this later HRRR scenario plays out, that could limit daytime heating and associated recovery in the wake of the first round of storms, which would then decrease the threat or strong to severe storms during the second round of storms in the later afternoon and evening. However, if activity moves through by midday, enough recovery is expected to keep the threat for strong to severe storms in place with the second round. The evolution of convection over the next 6 hours should provide a clearer picture of what will happen later today. Otherwise, the going forecast remains on track with additional chances for showers and storms through the weekend and into the start of next week as temperatures remain above normal.

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 /06Z TAFS THROUGH 06Z FRIDAY/

Issued at 1258 AM CDT Thu Sep 3 2026

VFR conditions will remain in place through much of the period. Some fog may develop early this morning, mainly at HIB. There is the potential for two rounds of showers and thunderstorms across the region later today with one during the morning into early afternoon and a second for the late afternoon into evening hours. Depending on the timing of the first round of storms, the second round may be strong to severe. Conditions are expected to deteriorate following the second round of storms with areas of fog and low ceilings developing, but this may hold off until after 06z Friday. Easterly winds will be a bit breezy through the day today with gusts to 15 to 20 knots at DLH, HIB, and BRD.

MARINE /FOR NEARSHORE WATERS OF WESTERN LAKE SUPERIOR/

Issued at 1258 AM CDT Thu Sep 3 2026

Easterly winds will increase this morning to 10 to 20 knots with gusts to 25 to 30 knots in the western arm and along the South Shore. Small Craft Advisories have been issued for this winds and resulting waves of 3 to 5 feet. Winds diminish slightly tonight, but quickly ramp back up Friday morning to 15 to 20 knots with gusts to 25 to 30 knots, highest along the North Shore and western arm. While the advisories currently in effect expire this evening, they may be extended through Friday as the period of weaker winds is expected to be only a few hours. Two round of showers and thunderstorms are expected for today, but are not currently expected to be strong or severe. The timing of the two round would be during the morning through midday/early afternoon with the second during the late afternoon into Friday night.

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

FIRE WEATHER

Issued at 1258 AM CDT Thu Sep 3 2026

Moisture is expected to move into the region today and linger through the weekend. This will help keep afternoon RH values above 50% today through Sunday. Gusty easterly winds are expected today and tomorrow, highest near Lake Superior. Two rounds of showers and thunderstorms are possible today with the first during the morning through midday/early afternoon and the second later this afternoon into tonight. Some of the storms during the second round may be strong to severe from the Brainerd Lakes area to the I-35 corridor and Spooner and areas to the 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 today to 1 AM CDT Friday for LSZ144-145. Small Craft Advisory from 3 PM this afternoon to 10 PM CDT this evening for LSZ148-150.