Zimmerman is a rural community located about 45 miles northwest of St. Paul, in Sherburne County, Minnesota, United States. The population was 2,851 at the 2000 census. U.S. Route 169 serves as a main arterial route in the city.
An outflow boundary, also known as a gust front, is a storm-scale or mesoscale boundary separating thunderstorm-cooled air from the surrounding air; similar in effect to a cold front, with passage marked by a wind shift and usually a drop in temperature and a related pressure jump. Outflow boundaries may persist for 24 hours or more after the thunderstorms that generated them dissipate, and may travel hundreds of miles from their area of origin.