textproduct: Duluth

KEY MESSAGES

- Hot weather with temperatures in the upper 80s and 90s are likely this weekend and early next week. Heat headlines may be needed as early as Saturday.

- Scattered strong to severe thunderstorms are possible late this afternoon and evening. Large hail to around ping pong ball size is the main threat, but damaging wind gusts and perhaps a tornado can't be ruled out.

- More showers and storms are possible Sunday afternoon and night. A few strong to severe storms may be possible.

- Rainfall and storms will be here and there in the next week, but not really a good soaking in sight unless you get lucky with a thunderstorm.

UPDATE

Issued at 159 AM CDT Fri Jul 24 2026

This morning, there is a broad shield of stratus roughly across the Dakotas/Minnesota border and points south. This will move northward with southwesterly flow through the morning and early afternoon. So, we will probably see some mostly cloudy skies for a good portion of the day around the region. This will create a caveat for convection potential later this afternoon and into tonight.

The stratus shield will likely remain a bit east of where the initial convection will fire later this afternoon across the Dakotas and into western Minnesota, so not too much change in the forecast there. These clouds could mean that we end up with a bit less instability in the Northland, which could lessen their intensity as they move east into the evening. At the very least, the stratus layer tilts the odds in favor of the thunderstorms being largely elevated by the time they make it into the Northland, or at least once they move east into, say, St. Louis/Carlton/Pine counties and points east. With that said, the risk for surface-based convection still can't be ruled out if the cap can be eroded, and this is possible especially for north-central Minnesota. If this happens, lower-atmospheric sounding profiles have quite a bit of speed and directional shear that would favor supercell storm mode and introduce damaging winds and perhaps a tornado as possibilities in addition to the primary hail hazard that storms will have whether they are surface-based or elevated.

Overall MUCAPE potential is looking somewhat impressive, with 1-2 kJ/kg at a minimum, but it could even be a little higher than that. We've been advertising hail up to ping pong ball size, but honestly, golf ball size or larger couldn't be completely ruled out with a storm or two, mainly in far north- central Minnesota where there's the best potential for surface- based storms. Storms will be aided by an upper-level trough, so there is some chance that some of these storms could retain some intensity into the evening and early overnight as they move east, but they should gradually weaken overnight.

On Saturday, plenty of warm air advection will bring the first of the hot weather into the region. It's looking like we should be capped despite elevated instability, so thunderstorms are not likely. On Sunday, some synoptic support aloft with some passing short waves may be enough to bust the cap. In that case, plentiful instability and shear could result in some scattered strong to severe storms.

Beyond that, no other major changes from the previous discussion.

DISCUSSION

Issued at 1213 PM CDT Thu Jul 23 2026

For the rest of today and tonight across the Northland, generally quiet and seasonable conditions will prevail. High pressure keeps our skies mostly sunny with afternoon temperatures reaching the lower to mid 80s. A stray shower or isolated storm might pop up near the International Border this afternoon, but most locations will remain completely dry. Overnight lows will comfortably drop into the upper 50s and lower 60s under mostly clear skies.

Friday will feature a noticeable increase in heat and humidity ahead of an approaching cold front. As this front pushes into the region, we are monitoring a severe threat for Friday afternoon and evening across north-central Minnesota. The primary hazards with these elevated storms will be large hail up to ping pong ball size and damaging wind gusts. This particular impulse is leftover convection that should be dying or on the downhill as it moves from the Dakotas into Minnesota. Some storms may hold together to pose a threat especially if they stay in a line.

Behind the front on Saturday, conditions dry out, but the heat quickly builds back in as an upper-level ridge amplifies over the region. Hot temperatures are showing up in some of the guidance for Sunday and Monday, which could push heat temperatures well into the 90s and possibly the low 100s. In addition to the sweltering conditions, another severe threat exists again on Sunday as a mid-level boundary sets up across the area. The range in guidance for max t's likely exists as the convective threat would likely steal the energy for storms rather than heat. That is probably the likely scenario, so not hitting the heat headlines too hard. There is a small cap which also suggests convection may win out. It will be interesting to see how the higher rez convective allowing models pan out for this.

The unseasonably hot and humid pattern will persist into early next week, with Monday remaining quite hot across the Northland. A few lingering, isolated showers or storms are possible Monday into Tuesday, but the strong upper ridge will suppress most widespread activity. By the middle of next week, temperatures may moderate slightly back into the 80s, but the overall pattern remains largely dry across the region. Although we will see scattered showers and storms, rainfall will be here and there, but not really a good soaking one is in sight aside from if you get lucky from a thunderstorm.

The 6-10 day CPC outlook for the Upper Midwest and Great Lakes region favors a strong probability of above normal temperatures as an upper level ridge dominates the central United States. Precipitation across our area leans toward below normal probabilities.

AVIATION /06Z TAFS THROUGH 06Z SATURDAY/

Issued at 1246 AM CDT Fri Jul 24 2026

Quiet weather with VFR conditions for the rest of the morning. Wind speeds will be gradually increasing from the southwest with gusts to around 20 kt by around 18z, persisting into the afternoon and evening. With warm air advection ongoing through the period, some MVFR stratus is looking more likely to develop around midday and persist for several hours at some terminals, with the highest confidence at HIB/BRD and possibly DLH. Ahead of a cold front, there will be a chance for showers and thunderstorms, especially at INL/HIB during the late afternoon and especially evening. Some of the afternoon stratus may have an impact on when thunderstorms may develop, but went with the best estimate on timing that's available now. Storms could be strong to severe with large hail being the main threat, but damaging winds to 50-60 kt not totally out of the question (5-15% chance).

MARINE /FOR NEARSHORE WATERS OF WESTERN LAKE SUPERIOR/

Issued at 159 AM CDT Fri Jul 24 2026

Gusty southwest winds are expected to develop through today and linger into tonight. Winds are expected to gust between 20 and 30 kt this afternoon through most of tonight. I did nudge winds towards the higher end of guidance with potential for winds gusting in the 25-30 kt range to mix down. As such, Small Craft Advisories have been issued everywhere starting this afternoon and gradually ending later tonight into early Saturday morning. The last headline to end will be near Grand Marais to Grand Portage, where the gusty winds may last the longest into Saturday morning.

In addition to strong southwest winds in general, there is a chance for showers and thunderstorms this evening and overnight, which may result in gusty and erratic winds and perhaps some small hail.

Winds will calm down on Saturday, become light and variable Saturday night, then become light from the northeast on Sunday.

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

FIRE WEATHER

Issued at 1213 PM CDT Thu Jul 23 2026

Elevated fire weather conditions are possible today as minimum relative humidity values drop to 30 to 40 percent alongside southwest wind gusts of 15 to 20 mph. Winds will remain breezy on Friday and into the weekend as hot temperatures build across the region. With afternoon relative humidity values hovering between 35 and 45 percent and only isolated chances for wetting rain, the general trend will feature drying fuels and near- critical conditions through early next week. Friday gives the best chance for wetting rain over the wildfire areas near the Intl Border. Hot and dry with periodic gusty winds to 25 mph through the forecast. Several wind switches too, but Friday looks to be the gustiest day.

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 from 3 PM this afternoon to 7 AM CDT Saturday for LSZ121-146>148-150. Small Craft Advisory from 3 PM this afternoon to 10 AM CDT Saturday for LSZ140. Small Craft Advisory from 3 PM this afternoon to 4 AM CDT Saturday for LSZ141>145.