textproduct: Duluth

KEY MESSAGES

- Widespread showers and thunderstorms continue this morning. A few storms may become strong, capable of producing wind gusts of 40mph, small hail, and very heavy rainfall. - Strong west-northwest winds are very likely on Wednesday, with gusts of 30 to 40 mph forecast. Winds are most likely to be strongest in the Minnesota Arrowhead.

- Additional precipitation chances arrive late this week into the weekend. A pattern change to cooler temperatures is favored this weekend into early next week.

DISCUSSION

Issued at 144 AM CDT Tue Sep 8 2026

A warm front extending from a surface low centered over south central Canada stretches west to east just north of the Canadian border this morning, with dewpoints in the 60s across the Northland. A cold front extends southward from that surface low through the Plains. Ahead of the cold front, southerly flow continues to bring moisture northward. In response to a strengthening LLJ, clusters of showers and storms developed overnight and are moving northeastward, generally south of the US-2 corridor in north central MN and now approaching the Twin Ports and moving into northwest WI. Additional showers have developed across the Arrowhead. Despite PWs around 1.8 inches and locally heavy rainfall under the stronger storms, activity is transient and has not presented a flooding threat. There is sufficient MUCAPE for updrafts, but given relatively warm, saturated profiles and weak lapse rates, do not expect severe storms overnight. The ongoing storms will continue northeastward, likely still impacting the I-35 corridor and Twin Ports during the morning commute.

In it's wake, cloud cover will linger through the morning, but with the cold front still to our west, there is a chance of continued scattered showers. The front moves through the region this afternoon, and CAMs suggest a few storms could develop along that boundary. Lapse rates will be better with 50kts of bulk shear overlapping a nose of 500-1000 J/kg of CAPE (depending on model of choice) just ahead of the front. With widespread cloud cover, it could be difficult to realize that instability. If storms can develop, there could be strong storm or two.

Following the cold frontal passage, a more benign pattern settles over the CWA around mid-week as high pressure builds. Ahead of this high pressure, west-northwest winds are very likely to become strong during the daytime hours on Wednesday. Wind gusts of 30-40 mph are forecast, strongest in the Arrowhead. A few gusts in excess of 40 mph are not totally out of the question, although the NBM probability for inland locations along the North Shore is a low 10-20%. Wind Advisories may be needed on Wednesday, especially if winds show an increasing trend.

The next chance for precipitation arrives late into the week into the weekend as additional troughs potentially propagate through the CWA. One upcoming pattern change of note is a temperature change arriving this weekend into early next week. While high temps most of this workweek will be in the 70s for most, high temps by this weekend into early next week will likely be in the 60s (with a few upper 50s not out of the question!).

AVIATION /06Z TAFS THROUGH 06Z WEDNESDAY/

Issued at 112 AM CDT Tue Sep 8 2026

Clusters of showers and storms are moving through the Northland this morning, with potential impacts at all terminals through early Tuesday morning. Stronger storms could produce wind gusts to 35kts, frequent lightning, and heavy rainfall. Have timed out impacts based on current radar trends. There could be additional development before 12Z, with coverage expanding northward over the Arrowhead.

Expect breezy south winds outside of convection, with gusts to 20-25kts. Behind convection, a period of IFR/MVFR cigs is possible with cigs slow to lift through the morning. Winds will shift to the southwest Tuesday afternoon, with gusts to 20-25kts remaining possible.

There is a low chance of additional showers or storms Tuesday afternoon as a weak cold front moves through. Chances at any terminal are too low to include at this time.

MARINE /FOR NEARSHORE WATERS OF WESTERN LAKE SUPERIOR/

Issued at 144 AM CDT Tue Sep 8 2026

Southeast to south winds increase this morning, with widespread gusts of 25 knots or greater are expected across western Lake Superior, with gales expected from Grand Portage to Grand Marais. The Gale threat diminishes this afternoon, although a Small Craft Advisory will likely be needed for these nearshore waters. Widespread Gales continue to look likely for Wednesday as a tight pressure gradient develops. Therefore, a Gale Watch was issued across western Lake Superior on Wednesday.

Outside of the expected elevated winds, thunderstorms are forecast this morning. A few storms may be strong, capable of producing wind gusts in excess of 30 knots, small hail, and frequent cloud- to- water lightning.

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

FIRE WEATHER

Issued at 144 AM CDT Tue Sep 8 2026

Numerous to widespread showers and thunderstorms will continue across portions of the Northland early this morning with most of the activity along and south of US-2 in north central MN, expanding into the Arrowhead and across northwest WI. Additional rainfall amounts around 1 inch are possible from the I-35 corridor eastward, and along portions of the North Shore. Lesser amounts expected north of US-2 and across the Arrowhead.

Severe storms are not expected, but frequent lightning and gusty winds to 40 mph are possible with stronger storms. Outside of convection, strong southerly winds will gust to 25mph, turning to the southwest this evening, and diminishing.

Strong west-northwest winds are very likely to arrive on Wednesday, with the potential for gusts of 30-40 mph. Strongest winds on Wednesday are most likely to be in the Arrowhead, especially on exposed ridges. While winds will be strong, lingering moisture will result in min RH of 40% or greater on Wednesday afternoon. Winds ease Wednesday evening as high pressure builds into the area.

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 until 7 AM CDT Wednesday for LSZ121- 142>148-150. Gale Watch from Wednesday morning through Wednesday afternoon for LSZ121-140>148-150. Small Craft Advisory until 4 AM CDT early this morning for LSZ140. Gale Warning until 1 PM CDT this afternoon for LSZ140. Small Craft Advisory until 7 AM CDT Wednesday for LSZ141.