textproduct: Duluth

KEY MESSAGES

- Strong to severe storms over portions of NW Ontario, MN Arrowhead, and western Lake Superior are forecast to move southeastward with time and may expand in coverage over northwest Wisconsin later this morning.

- Storms are expected to depart the Northland by late morning or early afternoon.

- Warm and muggy conditions persist today well inland from Lake Superior. Clouds may limit temperatures and heat risk. A Heat Advisory may be needed.

- Warm temperatures continue this week, with occasional precipitation chances. The next significant chance of precipitation is Thursday into Friday.

UPDATE

Issued at 1149 PM CDT Sun Jul 26 2026

Storms have been going since this afternoon, but have been having a hard time strengthening to their full potential due to the cap seen in the low levels. However, instability and wind shear are still plentiful at 3000-4000 J/kg and 50 kts. However, the current convection could help to erode the cap to the point that thunderstorms will be able to tap into the ripe environment. Storms are still expected to remain elevated due to surface temperatures cooling overnight, but storms will primarily be capable of producing large hail. Storms will linger into the morning, when the chance for severe storms will start to lower.

Hot conditions continue today, though not quite hot enough for a heat advisory. Still, expect heat index values approaching 90 and dewpoints remaining soupy in the upper 60s. Smoke aloft may inhibit temperatures slightly, but not enough to bring relief.

DISCUSSION

Issued at 215 PM CDT Sun Jul 26 2026

Convective trends are the main concern for the rest of the day, with an MCV sliding out of the Manitoba, North Dakota, and Minnesota area to the east-southeast. It should move into the Northland this afternoon, bringing an initial round of showers and storms to the forecast area. The current convection is elevated in nature, tapping into the extreme amount of MUCAPE we saw on this mornings KINL upper air sounding. What this convection does over the next few hours is still somewhat uncertain. If it remains elevated and simply drifts to the southeast, we may have mainly a large hail threat. However, the airmass over our region is destabilizing, and we have 40 to 50 knots of 0-6km shear. If we can break the cap and the storms can become surface based, we could be dealing with an expanding QLCS and associated damaging wind threat. We are in wait and see mode for now. Additional storm development later this afternoon and tonight is going to depend on flow moving up over the 850mb baroclinic zone, and initiation will be difficult to forecast very far ahead of time. Apart from the storms, dangerous heat persists this afternoon, with temperatures already well into the 80s and Brainerd has risen above 90 already. The heat headlines, both warning and advisory, continue as is with hazy, smoky skies.

For Monday, temperatures temper slightly as winds shift to the northwest and bring in some drier air, but conditions will remain unseasonably warm. Heat indices will still approach the low 90s, especially in the Brainerd Lakes area. Isolated severe thunderstorms remain possible in the early morning as an upper level shortwave and cold front traverse the region. Any organized storms could produce large hail and damaging winds, mainly early in the day. Areas of wildfire smoke will also persist, keeping skies fairly hazy across the Northland.

High pressure builds into the region for Tuesday and Wednesday, bringing drier conditions and at least a few days off from the oppressive humidity. While daytime highs will remain above normal in the 80s to low 90s, the drier airmass will make it feel more comfortable across the region. Generally quiet, dry, and pleasant weather is expected to hold firm for both days with comfortable overnight lows in the upper 50s and 60s. Isolated, diurnally driven showers and storms may be possible during the afternoon and early evening.

Heading into Thursday and Friday, the quiet stretch comes to an end as the next shortwave trough and associated cold front approaches from the west. This system will bring our next widespread chance for showers and thunderstorms to the area. High temperatures will continue to reach the 80s, with humidity levels creeping back up slightly as southerly flow returns ahead of the advancing system.

As we move into next weekend, near to slightly above normal temperatures will persist. Afternoon highs will generally remain in the 80s. We will be in a somewhat stagnant pattern with the upper level ridge sliding east to over the Great Plains, keeping the storm track generally to our north. We may get occasional waves of showers and storms which dive across the area, but nothing consistent is appearing in the model runs just yet.

AVIATION /12Z TAFS THROUGH 12Z TUESDAY/

Issued at 700 AM CDT Mon Jul 27 2026

Thunderstorms will continue to move generally toward the southeast this morning and should stay east of the terminals. IFR/MFVR ceilings will gradually improve to VFR and scatter out later today. A few hours of gusty winds are possible late this morning into early afternoon. Fog may develop tonight though probabilities are too low to include at this time.

MARINE /FOR NEARSHORE WATERS OF WESTERN LAKE SUPERIOR/

Issued at 1149 PM CDT Sun Jul 26 2026

Marine fog has temporarily cleared due to storms over western Lake Superior, but could make a reappearance in the early morning that may require an extension in the Dense Fog Advisory through the morning. Otherwise northeast winds up to 15 kts are expected this afternoon before decreasing again overnight.

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

FIRE WEATHER

Issued at 1149 PM CDT Sun Jul 26 2026

Hot conditions continue, with heat index values approaching 90 today. Smoke aloft and a lake breeze is somewhat limiting the highest temperatures across the Minnesota Arrowhead and near Lake Superior today, but heat will move back in later this week. Relative humidity values will remain higher and are not anticipated to get much lower than 40% for the majority of the week. Today will be windiest, with northwest winds up to 20 mph possible this afternoon. Winds will shift back to the south to southwest tomorrow and will remain at 10 mph or less for the week.

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

DLH WATCHES/WARNINGS/ADVISORIES

MN...None. WI...None. MARINE...Dense Fog Advisory until 10 AM CDT this morning for LSZ140>145.