A surface boundary extended into southeast Minnesota from an area of low pressure over southwest Minnesota on the afternoon of August 13th.  Favorable shear and instability existed along this boundary for supercell thunderstorms, which did develop in the early afternoon hours.  These thunderstorms produced tornadoes, along with severe thunderstorm winds, large hail and flooding.

Tornado in DODGE, MINNESOTA
From 13-AUG-10 14:22:00 to 13-AUG-10 14:46:00 (CST-6)
Location: HAYFIELD
Tornado F-scale: EF1
Property damage: 110.00K
Crop damage: 24.00K
Reported by: NWS Storm Survey

The tornado damage path began just south of State Highway 30 west of Hayfield.  The tornado did move off to the northeast nearing State Highway 56 before taking a north northwest track until it lifted just south of County Road 6.  Damage was noted to soybean and corn fields, numerous trees and limbs were snapped and uprooted, roofing damage occurred to a metal barn/shed, while an old barn was lifted off of its foundation for a complete loss.  Also, a local residence had some small beams knocked out from underneath a porch on the front of the house.

Hail in OLMSTED, MINNESOTA
From 13-AUG-10 17:41:00 to 13-AUG-10 17:41:00 (CST-6)
Location: EYOTA
Magnitude: 0.88 
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Trained Spotter

Hail in WINONA, MINNESOTA
From 13-AUG-10 18:00:00 to 13-AUG-10 18:00:00 (CST-6)
Location: ST CHARLES
Magnitude: 0.75 
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Emergency Manager

Heavy Rain in OLMSTED, MINNESOTA
From 13-AUG-10 15:00:00 to 13-AUG-10 18:36:00 (CST-6)
Location: BYRON
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Broadcast Media

Heavy rain fell in the city of Byron, with 3.10 inches measured.

Tornado in OLMSTED, MINNESOTA
From 13-AUG-10 16:40:00 to 13-AUG-10 16:40:00 (CST-6)
Location: ROCK DELL
Tornado F-scale: EF0
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Fire Department/Rescue

No damage was found after the tornado touched down briefly in a field.

Funnel Cloud in OLMSTED, MINNESOTA
From 13-AUG-10 15:50:00 to 13-AUG-10 15:50:00 (CST-6)
Location: ROCK DELL
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Amateur Radio

A funnel cloud was seen near the Dodge County line by spotters and amateur radio operators.

Flood in FILLMORE, MINNESOTA
From 13-AUG-10 22:34:00 to 14-AUG-10 02:30:00 (CST-6)
Location: CHATFIELD
Flood cause: Heavy Rain
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Law Enforcement

Water was over County Road 2 west of Chatfield.

Flood in OLMSTED, MINNESOTA
From 13-AUG-10 17:21:00 to 13-AUG-10 21:30:00 (CST-6)
Location: ROCHESTER
Flood cause: Heavy Rain
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Broadcast Media

Street flooding occurred through portions of Rochester. Also, at one local business, the water rose high enough to get into cars.

Thunderstorm Wind in DODGE, MINNESOTA
From 13-AUG-10 14:35:00 to 13-AUG-10 14:35:00 (CST-6)
Location: DODGE CENTER
Magnitude: 50.00 MG
Property damage: 0.00K
Crop damage: 0.00K
Reported by: AWOS

The automated weather observing equipment at the Dodge Center Airport measured a wind gust of 58 mph.

Thunderstorm Wind in WINONA, MINNESOTA
From 13-AUG-10 17:42:00 to 13-AUG-10 17:42:00 (CST-6)
Location: THE ARCHES
Magnitude: 50.00 EG
Property damage: 2.00K
Crop damage: 0.00K
Reported by: Emergency Manager

Several trees were blown down and water was over some roads in the Farmers Park area.

Funnel Cloud in OLMSTED, MINNESOTA
From 13-AUG-10 14:37:00 to 13-AUG-10 14:46:00 (CST-6)
Location: SALEM CORNERS
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Other Federal Agency

Air traffic controllers at the Rochester International Airport could see a funnel cloud to the southwest of the airport.

Hail in OLMSTED, MINNESOTA
From 13-AUG-10 17:21:00 to 13-AUG-10 17:21:00 (CST-6)
Location: SIMPSON
Magnitude: 1.00 
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Amateur Radio

The hail fell at the intersection of U.S. Highway 52 and Interstate 90.

Heavy Rain in OLMSTED, MINNESOTA
From 13-AUG-10 15:30:00 to 13-AUG-10 17:47:00 (CST-6)
Location: DOVER
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Trained Spotter

Heavy rain fell across the area, with 3.30 inches of rain measured 1 mile east of Dover. In the same time frame, 2.20 inches of rain fell at Chester Woods Park, located 2 miles east of Chester.

Flood in WINONA, MINNESOTA
From 13-AUG-10 18:30:00 to 13-AUG-10 22:30:00 (CST-6)
Location: ST CHARLES
Flood cause: Heavy Rain
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Emergency Manager

Street flooding was reported in the city of St. Charles.

Hail in DODGE, MINNESOTA
From 13-AUG-10 14:50:00 to 13-AUG-10 14:50:00 (CST-6)
Location: KASSON
Magnitude: 0.75 
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Trained Spotter