textproduct: Duluth

KEY MESSAGES

- Showers and thunderstorms start to affect the Northland this evening and overnight into Wednesday morning. Isolated to scattered severe storms are possible.

- A cold front brings another round of possible numerous severe thunderstorms Wednesday afternoon and evening. All hazards are expected if severe storms come to fruition, along with locally heavy rainfall.

- Hot temperatures are expected today and Wednesday when afternoon highs away from Lake Superior should be in the 80s to low 90s, with dew points in the 60s and 70s. Heat Advisories are in effect today and may be needed Wednesday.

- Additional light rain Thursday with cooling temperatures into the weekend.

DISCUSSION

Issued at 245 PM CDT Tue Jun 9 2026

THIS EVENING:

A warm front is slowly lifting over north-central to northwest MN this afternoon, allowing for very moist and hot air to overcome the Northland. Heat Advisories remain in effect for portions of the area where the worst of the heat and humidity is expected. While wind shear is lacking along this warm front, instability is plentiful with MUCAPE values of 3000-4500 J/kg. This has led to an agitated cumulus field with some convective attempts already early this afternoon. 12Z CAM guidance suggests that some showers and thunderstorms are possible for Koochiching County between now and 8pm. With that much instability, there is the potential than an isolated storm could produce severe hail or wind. However, there is also the potential that this warm front pushes further north and makes any storms Canada's problem.

Otherwise, expect dense fog over Lake Superior to push back inland this evening and overnight. A Dense Fog Advisory has been issued for areas along the North Shore and in the Twin Ports for the areas with the best chance of seeing visibilities drop below a quarter mile tonight.

TONIGHT-WEDNESDAY:

A strong upper level low and following troughing starts to move into our neck of the woods. The cold front associated with this low should traipse across the Dakotas today, expected to kick off a line of storms that accelerate away from the cold front and into the Northland sometime after midnight tonight. There is some significant variation on timing. We could see them getting in the Brainerd Lakes as early as 1-2am, or as late as 3-5am. Severe storm potential along this front is boosted by anomalous buoyancy and shear, and a strong mid level jet. There is the potential that this line could still be severe as it gets into our area, most likely an elevated wind and hail threat. If storms are able to stay surface based all the way into our area, there is a very slim tornado threat for the Brainerd Lakes to far NW Koochiching County.

Wednesday will see the cold front pushing smack across our area, buoyed by the same very unstable airmass that will affect the Dakotas the day before. This has the potential to lead to scattered to numerous severe storms in our area capable of producing all hazards as storms unzip along the cold front midday to early afternoon and then push east. However, there is some uncertainty with this setup, as lingering precipitation and convection Wednesday morning could have deleterious effects on an afternoon severe threat. High-res guidance is a bit of a mess when it comes to figuring out where and when storms might affect the area. The best chance for intense severe storms is over the I-35 corridor and into NW WI, but the entire area could see scattered severe storms at times with such a supportive environment. The best timing for severe storms to develop and push east is between 2-7pm on Wednesday, but there could be a stray storm possible outside of that range. Wednesday should be a decent rainmaker, with a decent chance for a widespread 0.5-1". There could be some locally higher amounts of 2- 4" that briefing lead to some ponding of water, but no widespread flooding is expected at this time.

Despite a very cold, stable airmass over Lake Superior, even those along the coastline should be prepared for severe storms tomorrow. First, the lake breeze is NOT expected to make it very far inland. While this could dampen the damaging wind threat if storms aren't too strong, large hail can crash through a the stable layer without any issue. Additionally, the lake breeze boundary can locally increase SRH which can intensify rotation and increase tornado potential.

Temperatures Wednesday ahead of any storms will be hot, but have trended down slightly. Expect afternoon highs to be in the 80s away from Lake Superior. Additionally, dew points in the 60s and 70s will make for a very sticky heat. Heat Advisories may be needed Wednesday for the I-35 corridor and east.

THURSDAY AND BEYOND:

Some additional wrap around precipitation may combine with a low pressure system to our south to produce additional showers and a few non-severe thunderstorms Thursday, along with relatively cooler temperatures. We stay in a zonal flow pattern into the weekend, stuck between a Hudson Bay low to our north and central Plains moisture to our south. This could make for some scattered showers at time, but nothing significant is expected.

AVIATION /18Z TAFS THROUGH 18Z WEDNESDAY/

Issued at 1233 PM CDT Tue Jun 9 2026

Mostly VFR conditions continue through this evening. A couple stray showers and maybe a thunderstorm could pop up and affect INL through this afternoon. At DLH, expect dense fog to return overnight. A line of showers and thunderstorms are expected to push across and affect all terminals from very late this evening through the early morning hours Wednesday. At DLH, these showers and thunderstorms might improve visibility. Elsewhere, a period of reduced ceilings and visibilities are expected. Some thunderstorms could become severe with strong winds and large hail, most likely for BRD and INL. Gusty south to southeast winds build across the area through Wednesday morning.

MARINE /FOR NEARSHORE WATERS OF WESTERN LAKE SUPERIOR/

Issued at 245 PM CDT Tue Jun 9 2026

Northeast winds continue over the next couple of days. Some afternoon gusts of 10-15 knots are possible at the head of the lake, but no additional small craft advisories are expected at this time in the near term. Patchy to widespread areas of dense fog are likely through Wednesday. A Marine Dense Fog has been issued through that period. Areas of fog will likely ebb and flow with some areas getting clear visibility at times. Expect showers and thunderstorms to return overnight into Wednesday morning with scattered showers and thunderstorms through Wednesday evening. Some storms could become severe, with damaging winds (best chance closest to shore), large hail, and frequent lightning. Overnight into Thursday, winds becoming southwesterly with some stronger gusts approaching 20 knots in the afternoon, especially along the North Shore. Additional rain showers are possible.

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

FIRE WEATHER

Issued at 245 PM CDT Tue Jun 9 2026

More thunderstorms return late this evening into Wednesday along a cold front moving from west to east. Scattered to numerous severe storms may be possible with this, especially on Wednesday afternoon and evening, but there is a risk for severe storms overnight into early Wednesday morning as well. All hazards are possible in these severe storms, including large hail, damaging wind gusts, and an isolated tornado. Good rainfall is expected, with widespread rainfall accumulations of 0.5-1.0"+ likely. Scattered showers Thursday, and then slowly drying out into the weekend.

See the Fire Weather Forecast product for a more thorough breakdown of fire weather conditions.

DLH WATCHES/WARNINGS/ADVISORIES

MN...Dense Fog Advisory from 10 PM this evening to 7 AM CDT Wednesday for MNZ020-021-037. Heat Advisory until 8 PM CDT this evening for MNZ010-011-018- 025-026-033>036-038. WI...Dense Fog Advisory from 10 PM this evening to 7 AM CDT Wednesday for WIZ001. Heat Advisory until 8 PM CDT this evening for WIZ006>008. MARINE...Dense Fog Advisory until 1 PM CDT Wednesday for LSZ121-140>148- 150. Dense Fog Advisory from 10 PM this evening to 7 AM CDT Wednesday for LSZ142.