textproduct: Duluth

KEY MESSAGES

- A few showers or storms are possible this evening for north- central Wisconsin. If storms develop, they could be strong to severe. - Warm and muggy conditions continue through the week, but do not anticipate needing Heat Advisories beyond today.

- Several rounds of showers and storms are possible Wednesday through the end of the week. Some of those storms may be strong to severe with the greatest risk during the period on Wednesday.

DISCUSSION

Issued at 255 PM CDT Tue Jun 30 2026

A "cool" front is pushing eastward through the Northland this afternoon, currently from near Crane Lake to Brainerd. The airmass is a bit cooler and drier behind the front, with dewpoints in the 50s. The combination of gradient winds (with low pressure centered over southern Manitoba) and afternoon mixing as temps warm into the 80s is allowing for breezy southwest winds with gusts of 25-30mph. There is a slight CU field finally developing near INL and Lake of the Woods, but do not expect much up growth and showers are not expected behind the front.

Ahead of the front, we cannot rule out a shower or storm this afternoon and evening. The best chances for this will be across the eastern third of northwest Wisconsin, roughly east of a line from Ashland to Hayward. With drier mid level air spreading eastward, the chances for convection will remain low. Dewpoints are lagging behind expected trends, as some of that drier mid level air is already mixing down, keeping dewpoints in the 60s. Breezy southwest winds will continue, and while some low level moisture could advect northward, it will battle with the incoming drier mid level air. There is instability pooling ahead of the front, with shear values around 40kts. So, if a storm can develop or move into northwest Wisconsin, it could be strong to severe through early evening.

Better storm chances will exist Wednesday morning and likely again during the afternoon, as upper level wave pattern remains active and warm temperatures push instabilities upward over the Northland. Tonight, convection is expected to develop across southern MN and push northeastward, reaching northwest WI Wednesday morning, after 8AM. Convection will be in part driven by a low level jet, which should weaken after sunrise. There is some question on the trajectory of this activity, with it riding along the frontal boundary moving through the Northland now. It is possible the strongest part of what is expected to be a MCS will push more eastward, following better jet features, and remaining along and ahead of the front. This would bring showers to portions of northwest Wisconsin Wednesday morning into the early afternoon, but likely not strong to severe storms. Lingering boundaries could allow for development through the day, as daytime heating maintains shower and storm chances.

Another round of strong to severe storms is possible Wednesday night, with development to our south, pushing eastward into central Wisconsin. Will continue to carry higher POPs for Wednesday evening, as some activity could expand northward into the area overnight into early Thursday morning. For both rounds Wednesday and Wednesday night, all severe weather threats are possible.

For Thursday through the upcoming weekend, the upper level pattern becomes more zonal over the northern CONUS with strong ridging remaining centered over the Mid Atlantic. The Northland will remain warm with slightly less humidity. Waves within the zonal flow will allow for occasional rain or storm chances, enhanced by daytime heating in the afternoon and evening. High temperatures will remain somewhat steady in the upper 70s and 80s. While not every day will be a washout, anyone with outdoor holiday weekend plans should monitor the forecast closely.

AVIATION /00Z TAFS THROUGH 00Z WEDNESDAY/

Issued at 612 PM CDT Tue Jun 30 2026

Beyond a few scattered thunderstorms for inland-north-central Wisconsin and patchy fog tonight, VFR conditions are expected to prevail. Gusty west-southwest winds before sunset this evening remain 5-10 knots overnight before becoming southwest again gusting to 20 knots Tuesday daytime again.

MARINE /FOR NEARSHORE WATERS OF WESTERN LAKE SUPERIOR/

Issued at 255 PM CDT Tue Jun 30 2026

Fog will continue to bring visibilities down this afternoon and in to the evening along the North Shore. Winds will increase from the southwest this evening, which should keep any fog confined to the locations north of Grand Marais. Southwest winds will be 15 kts or less Wednesday and Thursday, with the exception of locations north of Grand Marais. Conditions may become hazardous to smaller vessels during the afternoon and evening both days in that area, where winds could gust to 25kts, and small Craft Advisories may eventually be needed.

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

FIRE WEATHER

Issued at 255 PM CDT Tue Jun 30 2026

Warm temperatures and increased dewpoints are expected to continue, particularly in northwest Wisconsin, through the week. This will keep minimum RH values above 40 percent for most of the area each day. Slightly drier air in the Arrowhead could bring RH values down to around 35% each afternoon. Winds will be out of the west to southwest through Thursday, with gusts to around 20 mph. Winds diminish Friday from the northeast.

Occasional rain and storms are possible, particularly across northwest Wisconsin, but widespread wetting rains are not expected.

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

DLH WATCHES/WARNINGS/ADVISORIES

MN...None. WI...Heat Advisory until 7 PM CDT this evening for WIZ002>004-008- 009. MARINE...Dense Fog Advisory until 10 AM CDT Wednesday for LSZ140>142.