Duluth, Minn. – Northern Minnesota and northwest Wisconsin are facing two opportunities for strong to severe thunderstorms, with the first arriving overnight and another developing Monday afternoon into the evening. While not every community will see a storm, any thunderstorm that forms could quickly become severe with damaging winds, small to large hail and torrential rainfall.
According to the National Weather Service in Duluth, the first round of storms will move west to east overnight into early Monday. Forecast timing remains below average in confidence, but storms are expected to reach the International Falls and Bigfork areas between 10 p.m. and 2 a.m., spread toward Ely and Grand Marais from midnight to 5 a.m., move through the Duluth and Twin Ports region around 2 a.m. to 5 a.m., and reach northwest Wisconsin between 4 a.m. and 9 a.m.
A second round of scattered thunderstorms is expected to develop Monday afternoon and evening. Forecasters say storms that form may produce damaging winds, large hail and possibly an isolated tornado, with the greatest severe weather risk centered over northwest Wisconsin, although confidence remains conditional on storm development.
Rainfall totals will vary considerably because of the scattered nature of the storms. Between now and Wednesday morning, most locations are expected to receive 0.1 to 0.3 inches of rain, but heavier amounts are possible where thunderstorms repeatedly track over the same area. Duluth has a 52% chance of receiving at least 0.25 inches of rain, while Ely has a 76% chance, Grand Marais 67%, International Falls 67%, Brainerd 39%, Virginia 54% and Spooner, Wisconsin 49%.
Residents should have multiple ways to receive warnings overnight, secure loose outdoor items before storms arrive and avoid driving across flooded roadways. Additional forecasts and any severe thunderstorm or tornado watches will likely be issued if confidence in storm coverage increases Monday.
