Northwest winds behind a strong cold front have allowed smoke that originated from a large (60,000+ acres) wildfire in northeast Minnesota to spread over the tip of Lake Superior and has blown south/southeast into parts of central and eastern Wisconsin on Tuesday. This has caused hazy (or smokey) conditions that may persist into early Wednesday. Poor air quality, limited visibility, and the smell of smoke have all been reported across parts of central Wisconsin and especially over eastern sections of the state.
Until the wildfire becomes better contained, periods of smoke and reduced visibilities may be experienced over the next few days, depending on the wind direction.
The wildfire going in northeast Minnesota is known as the Pagami Creek Fire and has burned areas of the Boundary Waters Canoe Area Wilderness.
MODIS imagery from the polar-orbiting satellite Aqua, taken 3 PM on September 12, 2011. Notice the darker, grainy look of the smoke plume compared to the clouds elsewhere.