textproduct: Duluth

KEY MESSAGES

- Dry weather today through Wednesday for nearly all.

- Scattered showers and non-severe storms forecast Thursday into Friday. A few strong thunderstorms are possible Thursday for the Brainerd Lakes into east-cental MN and far western WI.

- Additional chances for scattered shower and thunderstorms next Monday and Tuesday.

DISCUSSION

Issued at 1155 AM CDT Tue Aug 18 2026

Dry weather will prevail for the Northland today through Wednesday night, though a few passing showers cannot be ruled out late this afternoon in inland north-central Wisconsin. High pressure moving in overhead tonight helps to create ideal radiational cooling, dropping temperatures into the low to mid-40s. Cold spots in the Arrowhead and along the Iron Range dip into the upper-30s tonight, but no frost is forecast.

Quiet and dry conditions continue through Wednesday with seasonal high temperatures in the upper 70s. The next shortwave moves through the area on Thursday and brings a 45 to 70 percent chance of showers and non-severe thunderstorms. A warm front sets up and brings instability that is forecast to build to around 1000 J/kg of CAPE, PWATs approaching 1.5 inches, bulk shear of 45-50 knots and mesoscale forcing associated with the shortwave system. A few strong thunderstorms are possible for the Brainerd Lakes to east-central Minnesota and into far western Wisconsin Thursday late afternoon to early evening.

A cold frontal passage on Friday keeps widely scattered post-frontal showers in play for Friday daytime, along with non-severe thunderstorms into the Arrowhead to the Twin Ports and across northwest Wisconsin. Following the front, a mild and very nice weather weekend is coming up for our region. Temperatures will remain pleasant in the 70s with mostly sunny skies.

The next weather system after the Thursday and Friday one brings rain shower and thunderstorm chances back to the area early Monday morning into Tuesday. This progressive pattern will continue to provide periodic precipitation chances.

AVIATION /18Z TAFS THROUGH 18Z WEDNESDAY/

Issued at 1136 AM CDT Tue Aug 18 2026

VFR conditions will generally prevail for all regional TAF sites over the next 24 hours. Northwest winds will occasionally become gusty this afternoon around 15 to 20 knots before tapering off and becoming light and variable tonight under clear skies. A localized shower cannot be entirely ruled out in northwest Wisconsin this afternoon, but terminal impacts are not anticipated.

MARINE /FOR NEARSHORE WATERS OF WESTERN LAKE SUPERIOR/

Issued at 1137 AM CDT Tue Aug 18 2026

Southwest winds will increase this afternoon from Grand Portage to Grand Marais, generating gusts up to 25 knots and waves of 1 to 3 feet, resulting in a Small Craft Advisory through this evening. Winds will shift to the northwest and decrease tonight. Expect generally light winds on Wednesday before another system brings rain and thunderstorm chances to western Lake Superior by late Thursday and Friday.

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

FIRE WEATHER

Issued at 1141 AM CDT Tue Aug 18 2026

Predominantly rain-free weather is expected today and Wednesday. Minimum relative humidity will drop to 35 to 45 percent this afternoon with northwest winds gusting up to 18 mph. Deep mixing on Wednesday will drop humidity values to 28 to 38 percent for most locations, with light west to northwest winds. Showers and storms return Thursday along a weak warm front, with another round for Friday with a passing cold front. Light to moderate rainfall is forecast. The best potential for a few strong thunderstorms Thursday, along with very localized and brief heavy rainfall, is in the Brainerd Lakes to east-central MN and into west-central WI.

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 PM CDT this evening for LSZ140.