Historic December storm spawned at least 16 tornadoes in Minnesota

The National Weather Service confirmed that 16 tornadoes touched down in Minnesota during last Wednesday's unprecedented storms that brought damage to a large swath of the southern and southeastern parts of the state.

And the number could still rise as crews continue to survey the damage left from the fierce Dec. 15 outbreak, the National Weather Service said.

Minnesota had never had a tornado in December, so when the first touched down at 6:56 p.m. that day southwest of Alden in Freeborn County it launched the city into the state record book. Another tornado touched down to the north of town a few minutes later followed by more across Freeborn, Mower, Houston, Wabasha, Fillmore and Winona counties.

"This was a mindboggling feat," said Kenny Blumenfeld, senior climatologist with the Minnesota State Climatology Office. "We were seeing signs that severe weather was possible, but we did not expect a full-on damaging outbreak."

In Preston, in Fillmore County, crews on Tuesday were still cleaning up the mess from a twister with 80-mph winds that tore through town, toppling power lines and felling scores of trees, including one that fell on the mayor's house. The fire hall sustained some roof damage as did a few other city buildings, but nobody was hurt.

The town is recovering, said City Administrator Joe Hoffman, and Preston hopes to get money from the Federal Emergency Management Agency (FEMA) to help cover the cost, which is still being tallied, Hoffman said.

The tornado that hit Preston was one of five in Fillmore County, which borders Iowa in the southeast corner of the state. Twisters also were confirmed in Sumner Township, Carrolton Township, Arendahl and Rushford Village, the Weather Service said.

Freeborn County had the most twisters with six, including one that struck Hartland, just after 7 p.m. The tornado downed trees and power lines and delivered significant damage to downtown commercial buildings. The tornado had maximum winds of 115 mph, was on the ground for 2.17 miles and was the strongest of those reported Dec. 15, the Weather Service said.

Two separate tornadoes struck about 7 p.m. near Alden, also in Freeborn County. A twister with winds of 105 mph traveled from near 180th Street to near Interstate 90. A second tornado with winds of 100 mph formed north of I-90 and traveled 1.6 miles before dissipating, the Weather Service said.

Tornadoes in Freeborn County also were confirmed near Hayward, London and Myrtle, the Weather Service said.

One tornado touched down near Plainview in Wabasha County and one confirmed in Houston County near Money Creek was on the ground for nearly 7 ¹⁄₂ miles, the Weather Service said. Twisters also were confirmed in Winona County, with touch-downs near Wyattville and Homer.

A line of severe storms that had moved through Kansas, Nebraska and Iowa crossed into Minnesota and hit the area with widespread 60 to 80 mph wind gusts. The storms brought record high temperatures in the 50s and 60s and dragged muggy air more common to May and June into the state. That was all that was needed to set the table for the destructive events of last week.

"If you have the right ingredients — warm moist air and strong winds aloft — you can have a tornado," Blumenfeld said. "Tornadoes are geographically blind. They can happen anytime where those ingredients are present."

While historic for December, Wednesday's outbreak was not the state's worst. That happened on June 17, 2010, when 48 tornadoes touched down in 22 counties across Minnesota over six hours, the Climatology Office said.