textproduct: Duluth

KEY MESSAGES

- Warming trend starts today with temperatures running well above normal starting Monday and persisting through much of net week. Humid conditions are expected as well and heat headlines will likely be needed.

- A conditional chance for strong to severe storms exists for Sunday and Monday with additional chances for storms throughout next week.

UPDATE

Issued at 127 AM CDT Sat Jun 27 2026

Increasing winds today will lead to hazardous swimming conditions from rip currents at beaches along Lake Superior today. This trend will likely continue into Sunday as well.

Trend continues for the chance for strong to severe storms Sunday and Monday, though storms may be inhibited by the still- present cap expected in place aloft. However, elevated storms are still in play with heavy rain chances persisting and ponding possible, especially on Monday. In addition, whatever storms do manage to form will lead to lingering cloud cover into Monday and/or Tuesday, which may limit the heat threat to more of an advisory level rather than warning across the area. On top of that, models still seem to trend too hot this far out, so brought the temperatures down again slightly.

DISCUSSION

Issued at 1232 PM CDT Fri Jun 26 2026

High pressure was located across the western Great Lakes early this afternoon and it extended westward into the Central and Northern Plains. A narrow band of showers stretched from central North Dakota into central Minnesota and western Wisconsin in association with a weak shortwave aloft. Much of this activity was not reaching the ground and drying up as it moved to the east. A lake breeze was also observed on radar along the South Shore and head of the lake stretching from near Port Wing to near Moose Lake. Conditions are expected to remain mainly dry across the Northland today into tonight, outside of a few light showers in western areas as the shortwave aloft moves through.

Upper level ridging will build in for the weekend with return flow in the low levels on the back side of the departing high pressure. This will bring increasing temperatures and moisture northward into the Upper Midwest. Highs Saturday will reach into the 70s to lower 80s for both Saturday and Sunday with dewpoints in the 50s and 60s Saturday and 60s and 70s Sunday. Low pressure across the northern High Plains will move northward Saturday into Sunday, blocked by the strong high pressure to the east. As another area of low pressure develops along the cold front across the central High Plains, a warm front will lift through the Central Plains and Upper Midwest Sunday, bringing chances for showers and thunderstorms to the region. As this feature lifts northward, it will be accompanied by rich low level moisture and increasing lapse rates. This will bring a chance of strong to severe storms, but forecast soundings show capping in place, so storms may end up elevated. These storms may be efficient rain producers as well with tall skinny CAPE profiles and PWATS in the 1.5-1.75" range.

Monday continues to look interesting with very hot and humid conditions along with the potential for severe storms. Low pressure will move northward across the Central and Northern Plains through the day Monday along the west side of the upper ridge. Even more warm and more moist air will move northward into the region. Highs will reach into the 80s and 90s with dewpoints in the 60s and lower 70s. This package has lowered temperatures a few degrees for Monday to account for the strong warm bias noted in some of the models. Even with this change, heat indicies will reach into the 90s and potentially lower 100s in southern and western areas and heat headlines will likely be needed. This hot and moist airmass will lead to CAPE in excess of 3000 J/kg along with shear around 35 knots and favorable lapse rates. Forecast soundings continue to show a stout cap in place with very warm temperatures over 20C up to around 750mb. Should this cap hold, we might not see any storms. However, if updrafts can break through it, conditions will be favorable for all modes of severe weather Monday afternoon into Monday night. Heavy rainfall will continue to be a possibility during this time with PWATs above the 90th percentile for late June. With all this said, there aren't any strong indications of a lifting mechanism to get things going, so this is a very conditional threat and may rely on more mesoscale processes for initiation which cannot yet be resolved.

The remainder of next week will remain very warm with highs in the 80s and low 90s. Additional chances for showers and storms will be seen potentially each day. The mid-week period may not be as humid with models showing some drier air arriving behind a front Tuesday, but it remains to be seen how much of an effect this will have on providing any meaningful relief from the heat.

AVIATION /12Z TAFS THROUGH 12Z SUNDAY/

Issued at 646 AM CDT Sat Jun 27 2026

Scattered showers over north-central Minnesota may impact INL through 27.15Z. Some high-res models develop thunderstorms between 15Z and 19Z near INL. Left the PROB30 in the forecast for now. Shower chances at the remainder of the terminals dwindled as coverage became scattered over the past several hours. Additional storms are forecast Sunday though they are largely expected to arrive after 28.12Z.

MARINE /FOR NEARSHORE WATERS OF WESTERN LAKE SUPERIOR/

Issued at 127 AM CDT Sat Jun 27 2026

Winds increase during the day today and Sunday out of the northeast. Winds above 20 kts are expected at the Twin Ports, which prompted a Small Craft Advisory to be issued this afternoon and evening. Winds above 20 kts will expand at least up the North Shore for Sunday, which will likely lead to more Small Craft Advisory issuances.

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

FIRE WEATHER

Issued at 127 AM CDT Sat Jun 27 2026

Fire weather conditions are not expected, but we are expecting increasing temperatures and dewpoints into next week. Temperatures in the 80s and 90s and dewpoints in the 60s and 70s will lead to dangerous heat conditions. However, humidity in the afternoons will remain above 40% due to the high dewpoints. On and off chances for general and potentially severe thunderstorms will play a part in whether RHs remain higher as expected or if they will fall further if we stay dry. Winds will increase this weekend out of the southeast, with strongest winds Sunday with 15 mph sustained winds and up to 25 mph gusts.

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

DLH WATCHES/WARNINGS/ADVISORIES

MN...Beach Hazards Statement from 1 PM CDT this afternoon through this evening for MNZ037. WI...Beach Hazards Statement from 1 PM CDT this afternoon through this evening for WIZ001. MARINE...Small Craft Advisory from 4 PM this afternoon to 10 PM CDT this evening for LSZ144-145.