Warm advection ahead of a cold front moving from the Red River Valley into central Minnesota through the day lead to the development of storms by the late afternoon.  Large hail and strong winds were seen with these storms as they moved through the region. The winds knocked down a tree onto a trailer home, seriously injuring a young girl inside. Additional storms formed later in the evening as the cold front moved in.

Hail in CROW WING, MINNESOTA
From 31-AUG-18 19:00:00 to 31-AUG-18 19:01:00 (CST-6)
Location: LAKE HUBERT
Magnitude: 0.75 
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Trained Spotter

Hail in AITKIN, MINNESOTA
From 31-AUG-18 19:12:00 to 31-AUG-18 19:13:00 (CST-6)
Location: AITKIN
Magnitude: 3.25 
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Trained Spotter

Hail in AITKIN, MINNESOTA
From 31-AUG-18 19:13:00 to 31-AUG-18 19:14:00 (CST-6)
Location: AITKIN
Magnitude: 1.75 
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Law Enforcement

Hail in AITKIN, MINNESOTA
From 31-AUG-18 19:15:00 to 31-AUG-18 19:16:00 (CST-6)
Location: AITKIN ARPT
Magnitude: 1.75 
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Public

The hail shattered the back window of a vehicle.

Hail in AITKIN, MINNESOTA
From 31-AUG-18 19:48:00 to 31-AUG-18 19:49:00 (CST-6)
Location: SHESHEBEE
Magnitude: 0.88 
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Trained Spotter

Hail in AITKIN, MINNESOTA
From 31-AUG-18 20:20:00 to 31-AUG-18 20:21:00 (CST-6)
Location: TAMARACK
Magnitude: 1.00 
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Trained Spotter

Hail in ST. LOUIS, MINNESOTA
From 31-AUG-18 21:05:00 to 31-AUG-18 21:06:00 (CST-6)
Location: ADOLPH
Magnitude: 1.00 
Property damage: 0.00K
Crop damage: 0.00K
Reported by: NWS Employee

Hail in ST. LOUIS, MINNESOTA
From 31-AUG-18 21:13:00 to 31-AUG-18 21:14:00 (CST-6)
Location: (DLH)DULUTH INTL ARP
Magnitude: 1.00 
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Official NWS Observations

Hail in AITKIN, MINNESOTA
From 31-AUG-18 19:13:00 to 31-AUG-18 19:14:00 (CST-6)
Location: AITKIN
Magnitude: 2.75 
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Trained Spotter

Thunderstorm Wind in CROW WING, MINNESOTA
From 31-AUG-18 17:36:00 to 31-AUG-18 17:37:00 (CST-6)
Location: (P39)PEQUOT LAKES
Magnitude: 50.00 EG
Property damage: 0.00K
Crop damage: 0.00K
Reported by: State Official

Numerous trees were damaged along with downed power lines.

Thunderstorm Wind in CROW WING, MINNESOTA
From 31-AUG-18 17:45:00 to 31-AUG-18 17:46:00 (CST-6)
Location: CROSS LAKE
Magnitude: 50.00 EG
Property damage: 0.00K
Crop damage: 0.00K
Reported by: State Official

Multiple trees and power lines were downed by the storm.

Thunderstorm Wind in CROW WING, MINNESOTA
From 31-AUG-18 17:55:00 to 31-AUG-18 17:56:00 (CST-6)
Location: EMILY
Magnitude: 50.00 EG
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Trained Spotter

Many trees were snapped at a point 20 to 30 feet off the ground.

Thunderstorm Wind in AITKIN, MINNESOTA
From 31-AUG-18 18:14:00 to 31-AUG-18 18:15:00 (CST-6)
Location: WAUKENABO
Magnitude: 50.00 EG
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Law Enforcement

The roof of a trailer home collapsed and the home sustained other significant damage from the storm. A 10 year-old girl was trapped inside and her leg was crushed and fractured due to the damage. Downed trees were also blocking State Highway 3.

Thunderstorm Wind in AITKIN, MINNESOTA
From 31-AUG-18 18:15:00 to 31-AUG-18 18:16:00 (CST-6)
Location: HASSMAN
Magnitude: 50.00 EG
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Law Enforcement

A large tree was downed and blocking US Highway 169 just north of the State Highway 210 intersection.

Thunderstorm Wind in AITKIN, MINNESOTA
From 31-AUG-18 18:24:00 to 31-AUG-18 18:25:00 (CST-6)
Location: LIBBY
Magnitude: 50.00 EG
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Law Enforcement

A large swath of tree damage and downed power lines were observed between mile posts 127 and 136 along State Highway 65.

Thunderstorm Wind in AITKIN, MINNESOTA
From 31-AUG-18 18:25:00 to 31-AUG-18 18:26:00 (CST-6)
Location: LIBBY
Magnitude: 50.00 EG
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Public

A pontoon boat and a boat lift were flipped upside down on Big Sandy Lake.

Thunderstorm Wind in CARLTON, MINNESOTA
From 31-AUG-18 19:03:00 to 31-AUG-18 19:04:00 (CST-6)
Location: SAWYER
Magnitude: 50.00 EG
Property damage: 0.00K
Crop damage: 0.00K
Reported by: State Official

A few trees were knocked down along State Highway 210 between Cromwell and Cloquet.

Thunderstorm Wind in ST. LOUIS, MINNESOTA
From 31-AUG-18 19:25:00 to 31-AUG-18 19:26:00 (CST-6)
Location: BAYVIEW
Magnitude: 50.00 EG
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Amateur Radio

Two large trees were blown down and were blocking a road near Bayview School.

Thunderstorm Wind in ST. LOUIS, MINNESOTA
From 31-AUG-18 19:30:00 to 31-AUG-18 19:31:00 (CST-6)
Location: MISSABE JCT
Magnitude: 50.00 EG
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Public

A car was crushed by a fallen tree.

Thunderstorm Wind in ST. LOUIS, MINNESOTA
From 31-AUG-18 19:30:00 to 31-AUG-18 19:31:00 (CST-6)
Location: MISSABE JCT
Magnitude: 50.00 EG
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Public

A large tree was knocked down onto 8th Ave West.

Thunderstorm Wind in AITKIN, MINNESOTA
From 31-AUG-18 19:48:00 to 31-AUG-18 19:49:00 (CST-6)
Location: SHESHEBEE
Magnitude: 50.00 EG
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Trained Spotter

A few trees were knocked down by the storm.

Thunderstorm Wind in AITKIN, MINNESOTA
From 31-AUG-18 19:58:00 to 31-AUG-18 19:59:00 (CST-6)
Location: MINNEWAWA
Magnitude: 50.00 EG
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Public

Several pine trees were knocked down by the storm.

Thunderstorm Wind in CROW WING, MINNESOTA
From 31-AUG-18 17:53:00 to 31-AUG-18 17:54:00 (CST-6)
Location: EMILY
Magnitude: 50.00 EG
Property damage: 0.00K
Crop damage: 0.00K
Reported by: State Official

Many trees and power lines were blown down by the storm.

Hail in CARLTON, MINNESOTA
From 31-AUG-18 20:55:00 to 31-AUG-18 20:58:00 (CST-6)
Location: CLOQUET
Magnitude: 1.00 
Property damage: 0.00K
Crop damage: 0.00K
Reported by: NWS Employee

Thunderstorm Wind in CARLTON, MINNESOTA
From 31-AUG-18 21:00:00 to 31-AUG-18 21:01:00 (CST-6)
Location: SCANLON
Magnitude: 50.00 EG
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Public

A 30 foot tall tree was snapped about 8 feet from the top of the tree.