EF1 tornado in St. Louis County, Minnesota

The tornado developed east of the Burlington Northern Santa Fe railroad near the St. Louis River and tracked east-northeast for approximately 3.1 miles while producing sporadic pockets of low-end EF1 damage to softwood trees. The tornado struck a house which resulted in partial uplift of the roof and lofting of roofing materials. The tornado also flattened a decorative windmill and bent a flagpole. The roofing material was distributed downwind to a range of 380 yards. The tornado also snapped and uprooted several trees in this vicinity. The damage at this location was also rated EF-1. The sporadic damage track continued for another mile to the east-northeast. There was a distinct weakening of the tornado with several pockets of broken branches and limbs noted approximately 3 miles southwest of Zim. The tornado then turned southeast and the damage track tightened once again with a wide swath of EF-0 tree damage and pockets of low-end EF-1 damage. The sporadic EF-1 damage continued as the tornado crossed MN-7 and dissipated southwest of Stone Lake.

Tornadic thunderstorms formed in a very unstable airmass ahead of a cold front that moved through the area during the evening. Storms developed around 5 pm, and moved rapidly east, affecting much of northeast Minnesota and parts of northwest Wisconsin. Tornadoes, large hail and damaging winds occurred across parts of the area.

Damage surveys conducted by National Weather Service meteorologists confirmed 4 tornadoes over northeast Minnesota that evening. The strength of the tornadoes ranged from EF0 to EF2.