Tuesday dawned bright and brisk, a blustery day that felt perfectly normal for early March in Minnesota.
The day before, however, was anything but.
The National Weather Service confirmed that two tornadoes touched down in the state Monday night, one in the Sherburne County city of Zimmerman and the other in the Freeborn County city of Clarks Grove. The March 6 twisters blew away — by nearly two weeks — the record for the earliest reported tornado in the state, dating from March 18, 1968, near the southern Minnesota town of Truman.
"It's very unusual," said Todd Krause, warning coordinator meteorologist for the weather service in Chanhassen. "The fact that we've never had one this early speaks to just how unusual it is."
Several elements combined for the perfect storm, Krause said, including a strong jet stream and southern winds that brought warm, moist air to the state. But the final ingredient was a direct result of Minnesota's unusually mild winter: There was no snow on the ground.
"Bare ground allows for higher temperatures. When there's bare ground, the snow can't cool the air," Krause said. "If you have cold air in the last few hundred feet, it's harder for the tornado to reach the ground."
No injuries were reported from either twister, but damage was extensive in both locations from funnel clouds that touched down around dinner time Monday night.
Firefighters scrambled
In Clarks Grove, about a half-dozen members of the city fire department took a break from a scheduled training session Monday to step outside and watch the approaching storm roll in around 5:45 p.m.