textproduct: Duluth

KEY MESSAGES

- Hot and humid weather is expected starting Monday and lasting through next week. An Extreme Heat Watch has been issued for Pine/Burnett counties on Monday.

- A conditional chance for strong to severe storms exists for Sunday and Monday with additional chances for storms throughout next week.

DISCUSSION

Issued at 236 PM CDT Sat Jun 27 2026

There's a mix of weather conditions out there this afternoon with some areas basking in sunshine, and east-central Minnesota dealing with clouds and a bit of light rain with a ridge-riding shortwave passing by aloft. Expect this to move gradually northeast through the evening.

Tonight into Sunday: The first chances for thunderstorms We are still waiting to see how showers and thunderstorms will develop over the western Dakotas this afternoon. As will be the theme of the weather forecast for the next several days, what happens out west will determine what happens here ~12-24 hours later. Broad troughing, warm air advection, and plenty of instability will be available for storms to form this afternoon out west along a quasi-stationary and quasi north-south boundary. How exactly these storms will organize themselves and what the remnants will look like once they reach our area sometime around Sunday morning is still in question. There will be a strengthening low-level jet tonight to help sustain storms for a while, but as is often the case with late-morning arrival timing, storms will likely weaken by the time they get here. We will have a pretty strong cap in place ahead of these with strong warm air advection, so these storms should be elevated. We will have at least a small chance for some large hail if some of these storms can hold together.

Pretty robust instability should be in place by Sunday afternoon, and if we can get enough clearing and/or synoptic lift, we could get some more isolated to scattered strong to severe storms to develop. At this point, it looks like ridging and capping could dominate, but in this unstable environment, anything that can cause an updraft could create a strong to severe storm. SPC has outlined a slight risk for severe storms for north-central Minnesota with a marginal risk elsewhere for Sunday into Sunday night, and expect more changes to this forecast as we go towards Sunday morning and we know what kind of environment we will have Sunday morning for severe weather potential in the afternoon and evening.

Monday and Tuesday: The warmest air will arrive on Monday, and we can expect widespread highs in the upper 80s to mid 90s (cooler near Lake Superior with onshore flow). With these high temperatures and dew points in the 70s (about as high as they get in our region), expect some pretty oppressive heat. The highest confidence for moderate to major heat-related impacts will be east-central Minnesota into northwest Wisconsin, especially around southern Pine/Burnett counties. An extreme heat watch has been issued for these areas for heat indices that may reach around 105 degrees.

Instability will be pretty impressive...around 3k J/kg of MUCAPE. A capped environment with the strong warm air advection is the trick that makes thunderstorm forecasting difficult. We may see more storms form out west in the Dakotas where the quasi-stationary cold front slowly drifts east. At this point, we have just about equal chances of seeing some form of a severe weather outbreak from this Monday afternoon and night as we do not seeing much storm activity at all due to the capped environment. All hazards would potentially be possible if we can get storms to develop, so we recommend keeping a close eye on the forecast as the situation evolves.

A cold front will pass through as we go into Tuesday, and some lingering strong to severe storms can't be ruled out, especially in northwest Wisconsin where instability lingers. It will still be plenty hot on Tuesday, especially in northwest Wisconsin with highs in the low 90s, but a touch less hot on the Minnesota side (though most will argue that highs in the upper 80s is still pretty hot).

Wednesday into Next Weekend: A brief break from storms is looking likely Tuesday and Tuesday night, but going into Wednesday, another low pressure system out west will kick up more warm air advection, moisture advection, and instability into our region. This will keep us firmly within a hot summertime weather pattern, and we will probably see more thunderstorms. While it's several days out, strong to severe thunderstorms definitely seem plausible. We're going to stick with pretty messy southwesterly flow aloft to end the week and going into next weekend. We won't get much of a break from the heat except for areas near Lake Superior, and there should be more periodic storm chances.

AVIATION /18Z TAFS THROUGH 18Z SUNDAY/

Issued at 1256 PM CDT Sat Jun 27 2026

Light rain showers currently located in central Minnesota are expected to continue into the Arrowhead this afternoon and evening. Expectations are that visibility under these showers will remain VFR, although MVFR cigs have been observed upstream. Southeast winds will be gusty both this afternoon and especially on Sunday morning ahead of approaching low pressure. Shower and thunderstorm chances increase on Sunday, with KBRD most likely to see any thunderstorms in this period. As these showers and storms move into the area, cigs are anticipated to lower to MVFR and potentially IFR in KBRD.

MARINE /FOR NEARSHORE WATERS OF WESTERN LAKE SUPERIOR/

Issued at 236 PM CDT Sat Jun 27 2026

Breezy northeast winds this afternoon around the head of the lake will subside overnight, but strengthen again Sunday morning through the afternoon. Gusts to 25 kt are expected along the entire North Shore and along the South Shore to the Outer Apostle Islands. Small Craft Advisories will likely be needed.

More gusty east to northeast winds are expected on Monday, and small craft advisories may be needed again.

Expect periodic chances for showers and thunderstorms to develop. This afternoon and evening, a few showers are possible, but thunder is not expected. Sunday afternoon into Sunday night, thunderstorms will be possible at times. A stray strong to severe storm capable of producing large hail can't be ruled out. More storms may be possible Monday into Tuesday as well.

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

FIRE WEATHER

Issued at 236 PM CDT Sat Jun 27 2026

Expect warm to hot temperatures to develop, especially on Monday. The air mass will be quite humid though, with min RH above 50%. Drier conditions are possible Tuesday through Thursday with min RH falling into the ~35-45% range. There will be some breezy conditions at times Tuesday with gusts up to 20-25 mph, then less breezy for the rest of the week. There will be on and off chances for thunderstorms, and some may be strong to severe, over the next few days. Rainfall amounts are incredibly difficult to forecast due to the scattered nature of these storms. Some places may not see much rain while others may see an inch or more. With the amount of moisture and rain chances in place, fire weather risks are looking minimal.

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

DLH WATCHES/WARNINGS/ADVISORIES

MN...Beach Hazards Statement until 9 PM CDT this evening for MNZ037. Extreme Heat Watch from Monday morning through Monday evening for MNZ038. WI...Beach Hazards Statement until 9 PM CDT this evening for WIZ001. Extreme Heat Watch from Monday morning through Monday evening for WIZ006. MARINE...Small Craft Advisory until 10 PM CDT this evening for LSZ144- 145.