textproduct: Duluth

KEY MESSAGES

- The next chance for showers and storms will be tonight through Tuesday and again Wednesday.

- Severe storms are possible, particularly Tuesday afternoon and evening with the passage of a cold front.

- Seasonal, dry conditions return for the later part of this week.

DISCUSSION

Issued at 136 AM CDT Mon Aug 24 2026

Current conditions/this morning: High pressure is slowly sliding east this morning, with light and variable winds. Satellite imagery is showing some high level clouds pushing into the area from the west, but we will still have good radiational cooling conditions, and while I do not expect us to get quite as cold as last night, it will still be cool with lows in the 40s and perhaps upper 30s. Conditions will also be good for fog, bringing some patchy dense fog that will burn off quickly after sunrise.

Today: Southerly warm air advection will push highs up into the mid 70s to around 80 across the area. We have been watching the potential for showers and thunderstorms approaching the area with a wave of warm air advection early this morning, which we can see have developed over northern North Dakota as of 1 AM. However, most mesoscale analysis does not support this convection getting much farther east than it already is, and should deteriorate to mainly cloud debris before it gets to the Northland. Precipitation chances increase tonight as the main upper level shortwave moves across the area Tuesday into Wednesday. Tonight there will be enough instability and decent deep layer shear to initiate convection over eastern North Dakota, then gradually slide east overnight. However, like tonight, the instability and shear weakens significantly to the east, and the storms are likely to weaken and dissipate as they move east. We do have a sliver of Marginal severe risk just to our west from SPC, but it and the even farther west Slight risk are likely to be the main concern of the night and am less concerned for the Northland.

Tuesday: Warmer and more humid conditions push into the area, with surface based instability developing during the afternoon and evening hours. Then, just as the upper level shortwave moves across the area and deep layer shear parameters increase, there will be another wave of showers and thunderstorms which move across the Northland. These storms will have the potential to be strong to severe storms, with a few storms capable of producing 1" hail and damaging winds. SPC has a marginal risk (level 1 out of 5) outlined for all of the Northland.

Showers and non-severe storms will redevelop across the area on Wednesday in the cyclonic flow behind the upper level shortwave. While we will have mostly cyclonic flow on Thursday, the surface ridge building into the area and low level dry air should keep anything but diurnal cumulus from forming. Wednesday and Thursday will be cooler again as well.

Dry and seasonable conditions to continue into Friday with high pressure lingering over the area. Weak upper level ridging builds into the area for the weekend, with poor predictability for precipitation chances as weak shortwaves may slide through the flow aloft and bring a round of showers/storms. The forecast has some low end chances for precipitation, but these may be more limited than is currently depicted. Temperatures should remain near normal through the weekend. Another potent upper level low will progress across the area early next week, which may bring another round of higher confidence precipitation chances.

AVIATION /12Z TAFS THROUGH 12Z TUESDAY/

Issued at 635 AM CDT Mon Aug 24 2026

Patchy fog will be lifting over the next hour at KHIB as daytime heating begins. Conditions will be VFR today with increasing cloud cover as low pressure moves towards the area. Showers will be appearing on radar this morning into the afternoon, but little to no precipitation is expected at the surface due to low-level dry air. Shower and thunderstorm chances increase tonight in northeast Minnesota, with the greatest potential for thunderstorms being in KINL. Severe storms are anticipated to be just to the west, weakening as they enter the region tonight.

MARINE /FOR NEARSHORE WATERS OF WESTERN LAKE SUPERIOR/

Issued at 136 AM CDT Mon Aug 24 2026

Quiet conditions are expected across Western Lake Superior through today and tonight with waves of 1 foot or less and winds becoming easterly at generally less than 10 knots. Winds increase a little out of the southeast on Tuesday, along with shower and thunderstorm chances. We should have an initial wave of them Tuesday morning. Additional storms will develop during the afternoon and evening, some of which may be strong to severe. Shower chances to linger into Wednesday.

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

FIRE WEATHER

Issued at 136 AM CDT Mon Aug 24 2026

High pressure slides to our east today, allowing moisture to begin to push into the area from the west. Relative humidity values to be low again for the MN Arrowhead and northwest Wisconsin, but farther west in Minnesota RH values will increase to over 40 percent. Winds will become southerly today, and may gust around 10 mph during the afternoon for parts of the area. Shower and thunderstorm chances increase for Monday night through Wednesday, most especially on Tuesday afternoon and evening, when some storms may become strong. RH values to remain above 40 percent for both Tuesday and Wednesday. Precipitation chances are highest along and north of the Iron Range, but most areas have at least a 40 percent chance of a wetting rainfall.

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

DLH WATCHES/WARNINGS/ADVISORIES

MN...None. WI...None. MARINE...None.