textproduct: Duluth

KEY MESSAGES

- Chances for showers and storms this afternoon into tonight. A few may be strong to severe across mainly the Brainerd Lakes area.

- Chances for showers and storms linger for the holiday weekend with temperatures trending closer to normal. Easterly winds may lead to hazardous swimming conditions in the Twin Ports Saturday.

- Temperatures then return to above normal for much of next week with periodic chances for showers and thunderstorms.

DISCUSSION

Issued at 307 PM CDT Fri Jul 3 2026

High pressure was located both to the north and south of the Northland across northern Manitoba and the Ohio Valley. A stationary boundary was analyzed between these areas of high pressure from the Upper Peninsula of Michigan into northern Minnesota and South Dakota. A lake breeze was evident on radar along the South Shore of Lake Superior into far northwest Wisconsin. As instability builds this afternoon, isolated to scattered showers and thunderstorms are expected to develop across the region in the vicinity of the stationary boundary and possibly the lake breeze. Latest RAP analysis shows around 1500-3000 J/kg of CAPE in the Brainerd Lakes with effective shear less than 25 knots. RAP forecasts show shear becoming marginally better by around 00z, but still only around 25 to 30 knots. This will favor clusters of storms and pulse updrafts. With DCAPE of around 1000 J/kg, damaging wind gusts to around 50 to 60 knots look to be the primary threat with any storms. Some hail will also be possible with pennies being the most likely max, but a few reports of quarters cannot be ruled out given the strong instability in place.

As for timing and coverage of showers and storms through tonight, have leaned on the HRRR as a base and then adjusted from there. CAMs have not been doing well in this weakly forced regime, but most break out activity across the northern half of Minnesota in roughly the same time frame. Satellite shows cumulus bubbling across the region as of the time of this writing with some radar returns across central Minnesota, which is around an hour or so sooner than what the CAMs indicate. With the bulk of the instability centered across the Brainerd Lakes area, SPC has pulled the Marginal Risk area out of northwest Wisconsin and focused it across north-central Minnesota.

Convective evolution for overnight into Saturday remains in question given the weakly forced nature. However, better forcing looks to arrive through the day as an upper level shortwave moves in overhead while developing low pressure passes to the south. This may lead to more in the way of coverage for showers and storms through the day and into the evening hours. With a lot of uncertainty in place, trended POPs back towards the NBM for Saturday. This has led to a slight uptick in POPs with this package, mainly across southern areas closer to the developing low. Widespread cloud cover may limit instability and shear remains rather anemic, so no strong or severe storms are currently expected. If there is more sun during the morning and early afternoon, a few stronger storms cannot be ruled out. Additionally, with high pressure to the north and the developing low to the south, a tightening pressure gradient will set up across western Lake Superior and funnel easterly winds into the western arm of the lake. This will lead to an increased risk of rip currents along the beaches of Duluth and Superior. This will also push a lake breeze inland with 60s expected near the lake and into the Nemadji Valley with 70s and lower 80s elsewhere.

Surface high pressure will try and build in on Sunday, but an upper trough will remain in place which will keep chances for showers and a few thunderstorms in place. Temperatures will start to warm again with highs in the 70s and 80s. High pressure may keep dry conditions in place for Monday as temperatures further warm into the 80s. Rain chances then return for Tuesday into Thursday with temperatures remaining in the 70s and 80s.

AVIATION /18Z TAFS THROUGH 18Z SATURDAY/

Issued at 1251 PM CDT Fri Jul 3 2026

VFR conditions prevail across the Northland early this afternoon with some pockets of MVFR to IFR conditions, mainly from lingering low ceilings. Chances for showers and thunderstorms increase heading into late this afternoon and evening and have tried to time out some of the most likely times. There may be a second round later on this evening and overnight with more tomorrow morning. Given the overall low predictability of convection activity, there is reduced confidence in this timing. Have kept fog mentions in spots late tonight along with lowering ceilings that guidance agrees upon. This will result in MVFR conditions with the potential for lower if showers and storms are not occurring. Winds will generally be variable under 10 knots, but may be gusty and erratic in any storms that develop.

MARINE /FOR NEARSHORE WATERS OF WESTERN LAKE SUPERIOR/

Issued at 307 PM CDT Fri Jul 3 2026

Easterly winds of 5 to 15 knots will persist for this afternoon and tonight with the strongest winds at the head of the lake. With high pressure to the north and low pressure to the south for Independence Day, easterly winds will increase to 10 to 15 knots with gusts to 20 to 25 knots, highest in the western arm of the lake. These winds will generate waves of 3 to 5 feet near the Twin Ports and may lead to conditions hazardous to small craft. Winds then remain easterly for Sunday, but diminish to around 5 to 15 knots.

Dense fog has developed near the Twin Ports and may linger into this evening, although some improvement has been noted on satellite. There will be chances for showers and thunderstorms later this afternoon and tonight, but no severe storms are currently expected. Gusts to 40 knots and small hail will be possible along with cloud-to-water lightning. Additional showers and thunderstorms will be possible tomorrow and Sunday, but are note expected to be strong or severe.

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

FIRE WEATHER

Issued at 307 PM CDT Fri Jul 3 2026

Multiple chances for showers and thunderstorms will persist through the weekend and into early next week. Widespread wetting rainfall is not currently expected with activity more isolated to scattered in nature. Temperatures will trend slightly cooler for Independence Day with 70s and lower 80s expected away from Lake Superior with 60s near the lake and inland into the Nemadji Valley with a lake breeze. Minimum RH values will remain above 50 percent over much of the region with portions of the Arrowhead falling as low as 45%. Temperatures then warm back into the 70s to middle 80s for Sunday into Monday with RH values mainly above 40% with some pockets north of the Iron Range and into the Arrowhead into the 30-40% range. Winds will remain under 15 mph through the period with some higher gusts near the head of Lake Superior.

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 PM CDT this evening for LSZ144-145.