The afternoon of Friday, May 18th, the atmosphere was fairly dry near the boundary layer, but due to strong daytime heating, temperatures in the upper 80s, to lower 90s, steep lapse rates developed, and with ample instability above the boundary layer, thunderstorms developed.  These storms were high based, but with the steep lapse rates, and modest shear, large hail formed along with several severe wind gusts. More thunderstorms developed during the evening and caused large hail and severe wind gusts from Kandiyohi to Stearns, and Todd Counties.

Hail in BENTON, MINNESOTA
From 18-MAY-12 16:28:00 to 18-MAY-12 16:28:00 (CST-6)
Location: SARTELL
Magnitude: 0.75 
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Trained Spotter

Hail in BENTON, MINNESOTA
From 18-MAY-12 16:30:00 to 18-MAY-12 16:30:00 (CST-6)
Location: SARTELL
Magnitude: 0.75 
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Amateur Radio

Hail in STEARNS, MINNESOTA
From 18-MAY-12 22:24:00 to 18-MAY-12 22:24:00 (CST-6)
Location: SAUK CENTRE ARPT
Magnitude: 1.75 
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Trained Spotter

Hail in STEARNS, MINNESOTA
From 18-MAY-12 22:36:00 to 18-MAY-12 22:36:00 (CST-6)
Location: SAUK CENTRE
Magnitude: 1.00 
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Trained Spotter

Thunderstorm Wind in RENVILLE, MINNESOTA
From 18-MAY-12 16:35:00 to 18-MAY-12 16:35:00 (CST-6)
Location: BUFFALO LAKE
Magnitude: 52.00 EG
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Public

A large tree was blown down.

Thunderstorm Wind in SIBLEY, MINNESOTA
From 18-MAY-12 16:35:00 to 18-MAY-12 16:35:00 (CST-6)
Location: GIBBON
Magnitude: 52.00 EG
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Public

A large tree was blown down.

Thunderstorm Wind in MILLE LACS, MINNESOTA
From 18-MAY-12 16:19:00 to 18-MAY-12 16:19:00 (CST-6)
Location: MILACA
Magnitude: 68.00 MG
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Mesonet

A Minnesota Department of Transportation Wind Sensor measured a wind gust of 68 knots.

Hail in KANDIYOHI, MINNESOTA
From 18-MAY-12 20:40:00 to 18-MAY-12 20:40:00 (CST-6)
Location: WILLMAR
Magnitude: 0.75 
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Trained Spotter

Hail in KANDIYOHI, MINNESOTA
From 18-MAY-12 20:30:00 to 18-MAY-12 20:30:00 (CST-6)
Location: WILLMAR
Magnitude: 0.88 
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Trained Spotter

Hail in STEARNS, MINNESOTA
From 18-MAY-12 22:36:00 to 18-MAY-12 22:41:00 (CST-6)
Location: SAUK CENTRE
Magnitude: 1.25 
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Trained Spotter

The large hail stones accumulated up to 2 inches deep in some areas of town.

Thunderstorm Wind in STEARNS, MINNESOTA
From 18-MAY-12 21:49:00 to 18-MAY-12 21:53:00 (CST-6)
Location: BELGRADE
Magnitude: 56.00 EG
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Public

Several large trees were blown down from north of Belgrade, to Elrosa, Minnesota.

Hail in TODD, MINNESOTA
From 18-MAY-12 22:50:00 to 18-MAY-12 22:50:00 (CST-6)
Location: LITTLE SAUK
Magnitude: 1.00 
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Public

The large hail stones covered the ground.

Hail in KANDIYOHI, MINNESOTA
From 18-MAY-12 20:47:00 to 18-MAY-12 20:47:00 (CST-6)
Location: SPICER
Magnitude: 1.75 
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Public

Thunderstorm Wind in KANDIYOHI, MINNESOTA
From 18-MAY-12 20:47:00 to 18-MAY-12 20:47:00 (CST-6)
Location: SPICER
Magnitude: 52.00 EG
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Public

Several power lines were blown down and caused power outages around the area.

Thunderstorm Wind in MILLE LACS, MINNESOTA
From 18-MAY-12 16:30:00 to 18-MAY-12 16:30:00 (CST-6)
Location: PAGE
Magnitude: 61.00 EG
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Utility Company

Several large spruce trees and an energy power pole were blown down.