Updraft® - Minnesota Weather News

Minnesota's record tornado outbreak was 10 years ago

48 tornadoes skipped across Minnesota on June 17, 2010

June 17, 2010 tornado overview
June 17, 2010 tornado overview
Twin Cities National Weather Service

I remember where I was 10 years ago today.

I was on the air at MPR News with Tom Crann broadcasting tornado warnings for Minnesota’s biggest tornado outbreak on record. An incredible 48 tornadoes skipped across Minnesota that day. Here’s more on the outbreak from NOAA.

On June 17, 2010, a significant tornado outbreak occurred across the Northern Plains. Beginning around 2 PM, thunderstorms moved across the region, producing 74 tornadoes. Of those tornadoes, 48 were in Minnesota, eclipsing the single-day tornado record. At the time that it occurred, it went down as the 18th largest tornado outbreak on record in the United States, and the 2nd largest in the summer months of June-August.

Explosively unstable atmosphere

We knew the atmosphere was highly volatile leading up to June 17, 2010. NOAA’s Storm Prediction Center painted a moderate severe weather risk zone at 1 a.m. on June 17 right over Minnesota.

Severe weather risk areas for June 17, 2010
Severe weather risk areas for June 17, 2010
NOAA

As the heat of the day kicked in, thunderstorms exploded ahead of the advancing front.

Satellite loop from June 17, 2010
GOES-13 satellite loop from June 17, 2010
NOAA

Rapid storm initiation

Conditions were ideal for rapid storm development and updraft initiation. The Doppler radar loop shows dozens of discrete super cells exploding.

Radar loop from June 17, 2010
Radar loop from June 17, 2010
Twin Cities National Weather Service

30 super cells

NOAA reports 30 tornadic super cells tracked across the Upper Midwest that day.

Supercell tracks on June 17, 2010
Supercell tracks on June 17, 2010
NOAA

Numerous violent tornadoes

Yes, all tornadoes might be considered violent. But the term is reserved for the strongest (EF-3) and higher twisters. There were 8 tornadoes that rated EF-4 or EF-5.

June 17, 2010 tornado intensity ratings
June 17, 2010 tornado intensity ratings
Twin Cities National Weather Service

Damage was extensive in Wadena and other locations around Minnesota. Here’s Freeborn County.

June 17, 2010 tornado damage
June 17, 2010 tornado damage in Freeborn County.
Twin Cities National Weather Service

Twin Cities got lucky

The greater Twin Cities area was very lucky that day. Most of the severe weather developed west of the Twin Cities. The nearest tornado was in Wright County. There was an incredible display of Mammatus clouds as the storms rolled into the Twin Cities.

Mammatus clouds
Mammatus clouds in Chanhassen on June 17, 2010
Twin Cities National Weather Service