A significant, widespread severe weather outbreak occurred across a large portion of central and east central Minnesota. A powerful mid summer storm system over the western Dakotas, combined with warm moist air surging northward from the Gulf of Mexico, provided the ingredients for tornadoes, destructive winds, and large hail across parts of the Northland.
In addition, several storms in the Cass Lake and Lake Winnibigoshish area of north central Minnesota produced a large amount of one to two inch diameter hail, which is  about quarter to slightly larger than golf ball size.

Hail in CASS, MINNESOTA
From 17-JUN-10 12:47:00 to 17-JUN-10 12:47:00 (CST-6)
Location: BENA
Magnitude: 2.75 
Property damage: 15.00K
Reported by: Public

Most of the hail that fell was golf ball size.  A few larger stones up to baseball size were observed.  The hail was reported at the new Leech Lake Campground.  There was hail damage to vehicles, awnings, and buildings in Bena.

Hail in AITKIN, MINNESOTA
From 17-JUN-10 19:20:00 to 17-JUN-10 19:20:00 (CST-6)
Location: JACOBSON
Magnitude: 0.88 
Reported by: Trained Spotter

Hail in ITASCA, MINNESOTA
From 17-JUN-10 19:30:00 to 17-JUN-10 19:30:00 (CST-6)
Location: DEER RIVER ARPT
Magnitude: 0.75 
Reported by: Trained Spotter

The hail fell about 2 miles northwest of Moose Lake.

Thunderstorm Wind in ITASCA, MINNESOTA
From 17-JUN-10 13:15:00 to 17-JUN-10 13:15:00 (CST-6)
Location: INGER
Magnitude: 50.00 EG
Property damage: 1.50K
Reported by: Law Enforcement

Some small trees were blown down across a road near the east end of Lake Winnibigoshish.

Thunderstorm Wind in CROW WING, MINNESOTA
From 17-JUN-10 17:20:00 to 17-JUN-10 17:20:00 (CST-6)
Location: FIFTY LAKES
Magnitude: 50.00 EG
Reported by: Trained Spotter

Some tree branches were blown down.

Hail in CASS, MINNESOTA
From 17-JUN-10 11:57:00 to 17-JUN-10 11:57:00 (CST-6)
Location: BACKUS
Magnitude: 1.75 
Reported by: Trained Spotter

Hail in CASS, MINNESOTA
From 17-JUN-10 13:01:00 to 17-JUN-10 13:01:00 (CST-6)
Location: BENA
Magnitude: 1.00 
Reported by: Public

The hail was reported at the Nodak Lodge and Resort.

Hail in ITASCA, MINNESOTA
From 17-JUN-10 13:15:00 to 17-JUN-10 13:15:00 (CST-6)
Location: INGER
Magnitude: 1.00 
Reported by: Public

Hail in ITASCA, MINNESOTA
From 17-JUN-10 14:00:00 to 17-JUN-10 14:00:00 (CST-6)
Location: WIRT
Magnitude: 0.88 
Reported by: Amateur Radio

Tornado in AITKIN, MINNESOTA
From 17-JUN-10 19:05:00 to 17-JUN-10 19:06:00 (CST-6)
Location: HAYPOINT
Tornado F-scale: EF0
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Public

A tornado touched down briefly near Haypoint, in the Moose Willow State Wildlife Management Area.  There was little damage.

Hail in CASS, MINNESOTA
From 17-JUN-10 11:35:00 to 17-JUN-10 11:35:00 (CST-6)
Location: BACKUS
Magnitude: 1.75 
Reported by: NWS Employee

Hail in CASS, MINNESOTA
From 17-JUN-10 11:59:00 to 17-JUN-10 11:59:00 (CST-6)
Location: BACKUS
Magnitude: 1.00 
Reported by: Law Enforcement

Hail in CASS, MINNESOTA
From 17-JUN-10 12:10:00 to 17-JUN-10 12:10:00 (CST-6)
Location: HACKENSACK
Magnitude: 1.00 
Reported by: Trained Spotter

Hail in CASS, MINNESOTA
From 17-JUN-10 13:00:00 to 17-JUN-10 13:00:00 (CST-6)
Location: BENA
Magnitude: 1.75 
Reported by: Trained Spotter

Thunderstorm Wind in ST. LOUIS, MINNESOTA
From 17-JUN-10 15:39:00 to 17-JUN-10 15:39:00 (CST-6)
Location: SIDE LAKE
Magnitude: 50.00 EG
Property damage: 2.00K
Reported by: Law Enforcement

A few trees were blown down, and severe wind gusts bent pine trees to the ground.

Thunderstorm Wind in ST. LOUIS, MINNESOTA
From 17-JUN-10 15:50:00 to 17-JUN-10 15:50:00 (CST-6)
Location: LINDEN GROVE
Magnitude: 50.00 EG
Property damage: 4.00K
Reported by: Law Enforcement

Trees were blown down along Highway 1 near Linden Grove, as well as along Highway 5 South near Side Lake.

Thunderstorm Wind in ITASCA, MINNESOTA
From 17-JUN-10 13:30:00 to 17-JUN-10 13:30:00 (CST-6)
Location: BOWSTRING
Magnitude: 50.00 EG
Property damage: 1.00K
Reported by: Trained Spotter

Large branches 8 to 10 inches in diameter, along with a few trees, were blown down.

Thunderstorm Wind in CASS, MINNESOTA
From 17-JUN-10 12:47:00 to 17-JUN-10 12:47:00 (CST-6)
Location: BENA
Magnitude: 65.00 EG
Property damage: 15.00K
Reported by: Public

Substantial wind damage was reported.  The wind blew hard enough to blow water through seals around windows of the campground lodge.  A 100 pound access cover on the roof was thrown the entire length of the roof.  Siding and shingles were damaged and thrown about.  Covers were taken off the boat lift.  Trees were downed, and a few were uprooted and sheared off.

Thunderstorm Wind in ITASCA, MINNESOTA
From 17-JUN-10 13:15:00 to 17-JUN-10 13:15:00 (CST-6)
Location: INGER
Magnitude: 52.00 EG
Property damage: 6.00K
Reported by: Public

Winds were estimated at 60 mph, which blew down trees.  The hail and winds occurred at the Lake Winnibigoshish Resort and Campground.

Thunderstorm Wind in CASS, MINNESOTA
From 17-JUN-10 13:10:00 to 17-JUN-10 13:10:00 (CST-6)
Location: BENA
Magnitude: 50.00 EG
Property damage: 1.00K
Reported by: Public

Tree limbs were blown down due to the strong winds.

Tornado in CASS, MINNESOTA
From 17-JUN-10 16:37:00 to 17-JUN-10 16:48:00 (CST-6)
Location: POPLAR
Tornado F-scale: EF0
Property damage: 2.00K
Reported by: NWS Storm Survey

The tornado continued from Wadena County. Trees were snapped along its path, including County Road 2 and 64 up to the west side of Deer Lake.

Hail in ITASCA, MINNESOTA
From 17-JUN-10 14:00:00 to 17-JUN-10 14:00:00 (CST-6)
Location: MARCELL
Magnitude: 0.88 
Reported by: Trained Spotter

The hail fell at North Star Lake.

Hail in ITASCA, MINNESOTA
From 17-JUN-10 14:30:00 to 17-JUN-10 14:30:00 (CST-6)
Location: BOWSTRING
Magnitude: 0.75 
Reported by: Trained Spotter

A few dime and penny size hail stones fell.

Hail in ST. LOUIS, MINNESOTA
From 17-JUN-10 15:36:00 to 17-JUN-10 15:36:00 (CST-6)
Location: MEADOW BROOK
Magnitude: 0.88 
Reported by: Trained Spotter

The hail fell near Meadow Brook, or 10 miles east of Togo.

Hail in AITKIN, MINNESOTA
From 17-JUN-10 18:53:00 to 17-JUN-10 18:53:00 (CST-6)
Location: SWATARA
Magnitude: 1.75 
Reported by: Trained Spotter

Hail in AITKIN, MINNESOTA
From 17-JUN-10 19:20:00 to 17-JUN-10 19:20:00 (CST-6)
Location: HILL CITY
Magnitude: 0.88 
Reported by: Trained Spotter

Tornado in PINE, MINNESOTA
From 17-JUN-10 19:45:00 to 17-JUN-10 20:01:00 (CST-6)
Location: ROCK CREEK
Tornado F-scale: EF2
Property damage: 283.00K
Reported by: NWS Storm Survey

The severe storm that produced the tornado tracked northeast along the Saint Croix River Valley on the Minnesota-Wisconsin state border. Although the tornado crossed through mostly recreational land, residents between Rush City and Rock Creek in MN, as well as Grantsburg to Yellow Lake in WI were impacted. The maximum path width was a quarter mile, or 400 yards, with an average path width of 400 to 600 ft. The tornado exited Pine County at around 1955 CST, continuing on in Burnett County, WI, where it lifted at 2001 CST, about 3.5 miles northwest of Grantsburg, WI. The total path length was about 6.5 miles.
The worst of the damage occurred in far southeast Pine County and was evidence of a strong EF2 tornado with estimated winds of 110-135 mph. This rating was based on the total destruction of a strapped down mobile home and the extensive uprooting/snapping of trees where the tornado crossed Minnesota State Highway 70.  Two people in a mobile home were injured.  Multiple homes sustained significant damage.

Hail in CASS, MINNESOTA
From 17-JUN-10 13:10:00 to 17-JUN-10 13:10:00 (CST-6)
Location: BENA
Magnitude: 1.00 
Reported by: Public

Hail in AITKIN, MINNESOTA
From 17-JUN-10 19:27:00 to 17-JUN-10 19:27:00 (CST-6)
Location: JACOBSON
Magnitude: 1.50 
Reported by: Park/Forest Service

Also, a few trees were reported down in the Savanna State Forest, but damage was very sporadic.