Low pressure over South Dakota on May 27th was connected to a warm front across southern MN and southern WI. The warm front crept north...reaching a position about 100 miles south of Lake Superior during May 28th.  Rapidly moving troughs moved eastward along and just north of the warm front, resulting in severe convective weather and some rainfall reports of as much as 3 to 4 inches across northeast Minnesota.

Hail in PINE, MINNESOTA
From 27-MAY-12 19:03:00 to 27-MAY-12 19:03:00 (CST-6)
Location: HINCKLEY
Magnitude: 0.88 
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Trained Spotter

Hail in ST. LOUIS, MINNESOTA
From 28-MAY-12 14:30:00 to 28-MAY-12 14:30:00 (CST-6)
Location: PROCTOR
Magnitude: 0.75 
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Trained Spotter

Hail in CASS, MINNESOTA
From 28-MAY-12 13:15:00 to 28-MAY-12 13:15:00 (CST-6)
Location: LEADER
Magnitude: 0.75 
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Trained Spotter

Hail in PINE, MINNESOTA
From 28-MAY-12 14:44:00 to 28-MAY-12 14:44:00 (CST-6)
Location: ASKOV
Magnitude: 0.75 
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Trained Spotter

Hail in ST. LOUIS, MINNESOTA
From 28-MAY-12 14:20:00 to 28-MAY-12 14:20:00 (CST-6)
Location: DULUTH
Magnitude: 1.00 
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Trained Spotter

Hail in PINE, MINNESOTA
From 28-MAY-12 15:45:00 to 28-MAY-12 15:45:00 (CST-6)
Location: BRUNO
Magnitude: 0.75 
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Trained Spotter

Hail in ITASCA, MINNESOTA
From 28-MAY-12 15:59:00 to 28-MAY-12 15:59:00 (CST-6)
Location: GRAND RAPIDS
Magnitude: 0.75 
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Trained Spotter

Hail in CARLTON, MINNESOTA
From 28-MAY-12 13:14:00 to 28-MAY-12 13:14:00 (CST-6)
Location: CARLTON
Magnitude: 1.00 
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Trained Spotter

The hail covered the ground.

Hail in ST. LOUIS, MINNESOTA
From 28-MAY-12 13:47:00 to 28-MAY-12 13:47:00 (CST-6)
Location: ELDES CORNER
Magnitude: 1.00 
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Public

Hail in ST. LOUIS, MINNESOTA
From 28-MAY-12 13:55:00 to 28-MAY-12 13:55:00 (CST-6)
Location: NEW DULUTH
Magnitude: 1.75 
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Trained Spotter

The hail shredded leaves and damaged siding.

Hail in CROW WING, MINNESOTA
From 28-MAY-12 11:20:00 to 28-MAY-12 11:20:00 (CST-6)
Location: IRONTON
Magnitude: 1.00 
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Trained Spotter

Hail in AITKIN, MINNESOTA
From 28-MAY-12 11:29:00 to 28-MAY-12 11:29:00 (CST-6)
Location: AITKIN
Magnitude: 1.00 
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Trained Spotter

Hail in AITKIN, MINNESOTA
From 28-MAY-12 11:50:00 to 28-MAY-12 11:50:00 (CST-6)
Location: BENNETTVILLE
Magnitude: 1.75 
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Trained Spotter

Hail in CARLTON, MINNESOTA
From 28-MAY-12 13:10:00 to 28-MAY-12 13:10:00 (CST-6)
Location: SAWYER
Magnitude: 1.75 
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Trained Spotter

A wall cloud was also spotted.

Hail in CARLTON, MINNESOTA
From 28-MAY-12 13:10:00 to 28-MAY-12 13:10:00 (CST-6)
Location: SAWYER
Magnitude: 1.00 
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Trained Spotter

Hail stripped the leaves off trees.

Hail in CARLTON, MINNESOTA
From 28-MAY-12 13:10:00 to 28-MAY-12 13:10:00 (CST-6)
Location: SAWYER
Magnitude: 1.00 
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Trained Spotter

Hail in CROW WING, MINNESOTA
From 28-MAY-12 11:20:00 to 28-MAY-12 11:20:00 (CST-6)
Location: DEERWOOD
Magnitude: 0.88 
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Trained Spotter

Hail in CARLTON, MINNESOTA
From 28-MAY-12 13:25:00 to 28-MAY-12 13:25:00 (CST-6)
Location: CARLTON
Magnitude: 1.75 
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Trained Spotter

Hail in CARLTON, MINNESOTA
From 28-MAY-12 13:25:00 to 28-MAY-12 13:25:00 (CST-6)
Location: CLOQUET
Magnitude: 0.75 
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Trained Spotter

Hail in CARLTON, MINNESOTA
From 28-MAY-12 13:34:00 to 28-MAY-12 13:34:00 (CST-6)
Location: SAWYER
Magnitude: 1.00 
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Trained Spotter

The hail shredded leaves on trees.

Hail in ST. LOUIS, MINNESOTA
From 28-MAY-12 13:34:00 to 28-MAY-12 13:34:00 (CST-6)
Location: DULUTH HGTS
Magnitude: 1.50 
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Public

Flash Flood in PINE, MINNESOTA
From 28-MAY-12 15:32:00 to 28-MAY-12 15:32:00 (CST-6)
Location: WILLOW RIVER
Flood cause: Heavy Rain
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Public

Scotch Pine Road was washed out for 1000 yards at Highway 41.

Hail in CARLTON, MINNESOTA
From 28-MAY-12 14:36:00 to 28-MAY-12 14:36:00 (CST-6)
Location: CARLTON
Magnitude: 0.75 
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Trained Spotter

Flash Flood in ST. LOUIS, MINNESOTA
From 28-MAY-12 13:34:00 to 28-MAY-12 13:34:00 (CST-6)
Location: DULUTH HGTS
Flood cause: Heavy Rain
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Amateur Radio

Three inches of water covered 88th Avenue West at Grand Avenue.