A warm front was draped across the southern and southwestern reaches of the CWA during the day. By mid-afternoon, daytime heating led to two supercells developing along the warm front and traveling to the east-southeast along the front. Large hail and numerous trees were reported down, including quite a few trees in the Barnum, Minnesota, area from what appeared to be a microburst according to radar and damage photos.

Hail in ITASCA, MINNESOTA
From 28-JUN-18 09:45:00 to 28-JUN-18 09:46:00 (CST-6)
Location: GRAND RPDS SUGAR ARP
Magnitude: 1.25 
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Trained Spotter

Hail in ITASCA, MINNESOTA
From 28-JUN-18 10:06:00 to 28-JUN-18 10:11:00 (CST-6)
Location: BLACKBERRY
Magnitude: 0.75 
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Trained Spotter

Hail fell for about 5 minutes along with heavy rainfall.

Hail in ITASCA, MINNESOTA
From 28-JUN-18 10:26:00 to 28-JUN-18 10:28:00 (CST-6)
Location: BLACKBERRY
Magnitude: 1.75 
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Public

Thunderstorm Wind in CASS, MINNESOTA
From 28-JUN-18 12:28:00 to 28-JUN-18 12:28:00 (CST-6)
Location: REMER MUNI ARPT
Magnitude: 50.00 EG
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Trained Spotter

A large tree was snapped in half.

Hail in CASS, MINNESOTA
From 28-JUN-18 13:41:00 to 28-JUN-18 13:43:00 (CST-6)
Location: REMER MUNI ARPT
Magnitude: 1.00 
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Trained Spotter

Hail in CASS, MINNESOTA
From 28-JUN-18 14:00:00 to 28-JUN-18 14:02:00 (CST-6)
Location: PORTAGE LAKE
Magnitude: 0.75 
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Public

Thunderstorm Wind in CASS, MINNESOTA
From 28-JUN-18 14:00:00 to 28-JUN-18 14:00:00 (CST-6)
Location: PORTAGE LAKE
Magnitude: 50.00 EG
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Public

A few trees were blown down by thunderstorm winds.

Thunderstorm Wind in AITKIN, MINNESOTA
From 28-JUN-18 14:18:00 to 28-JUN-18 14:18:00 (CST-6)
Location: LIBBY
Magnitude: 50.00 EG
Property damage: 0.00K
Crop damage: 0.00K
Reported by: State Official

Multiple trees were knocked down in Savanna Portage State Park.

Hail in CARLTON, MINNESOTA
From 28-JUN-18 14:59:00 to 28-JUN-18 14:59:00 (CST-6)
Location: CROMWELL
Magnitude: 0.75 
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Public

Thunderstorm Wind in CARLTON, MINNESOTA
From 28-JUN-18 15:10:00 to 28-JUN-18 15:10:00 (CST-6)
Location: CROMWELL
Magnitude: 50.00 EG
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Public

A few trees were blown down by thunderstorm winds.

Thunderstorm Wind in CARLTON, MINNESOTA
From 28-JUN-18 15:40:00 to 28-JUN-18 15:40:00 (CST-6)
Location: BARNUM
Magnitude: 50.00 EG
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Amateur Radio

A thunderstorm microburst blew down 30-40 foot tall trees along Interstate 35 both north and south of the Barnum exit.

Thunderstorm Wind in CARLTON, MINNESOTA
From 28-JUN-18 15:40:00 to 28-JUN-18 15:40:00 (CST-6)
Location: MAHTOWA
Magnitude: 50.00 EG
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Public

Numerous trees were blown down across Highway 61 south of Mahtowa.

Thunderstorm Wind in CARLTON, MINNESOTA
From 28-JUN-18 16:28:00 to 28-JUN-18 16:28:00 (CST-6)
Location: BARNUM
Magnitude: 50.00 EG
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Public

A large pine tree that was blow down fell on a house.

Hail in AITKIN, MINNESOTA
From 28-JUN-18 15:52:00 to 28-JUN-18 15:54:00 (CST-6)
Location: MINNEWAWA
Magnitude: 0.88 
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Public

Hail in AITKIN, MINNESOTA
From 28-JUN-18 16:00:00 to 28-JUN-18 16:02:00 (CST-6)
Location: MINNEWAWA
Magnitude: 0.75 
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Trained Spotter

The hail shower was reported as intense.

Thunderstorm Wind in AITKIN, MINNESOTA
From 28-JUN-18 16:24:00 to 28-JUN-18 16:24:00 (CST-6)
Location: LAWLER
Magnitude: 50.00 EG
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Public

A few trees were blown down on County Road 13 east of Lawler.

Thunderstorm Wind in PINE, MINNESOTA
From 28-JUN-18 16:56:00 to 28-JUN-18 16:56:00 (CST-6)
Location: DENHAM
Magnitude: 50.00 EG
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Public

A few large trees, up to 16 inches in diameter, were blown down.

Hail in PINE, MINNESOTA
From 28-JUN-18 17:12:00 to 28-JUN-18 17:14:00 (CST-6)
Location: WILLOW RIVER
Magnitude: 1.00 
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Trained Spotter

Hail in PINE, MINNESOTA
From 28-JUN-18 17:23:00 to 28-JUN-18 17:35:00 (CST-6)
Location: BRUNO
Magnitude: 1.00 
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Trained Spotter

The hail fell for 12 minutes.

Hail in ITASCA, MINNESOTA
From 28-JUN-18 10:10:00 to 28-JUN-18 10:12:00 (CST-6)
Location: GRAND RPDS SUGAR ARP
Magnitude: 0.88 
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Trained Spotter

Nickel-sized hail fell on the far south side of Grand Rapids.

Hail in CASS, MINNESOTA
From 28-JUN-18 13:55:00 to 28-JUN-18 14:03:00 (CST-6)
Location: BENA
Magnitude: 1.75 
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Trained Spotter

Pea to golf ball-sized hail fell for over 7 minutes along with heavy rain.

Hail in CASS, MINNESOTA
From 28-JUN-18 14:13:00 to 28-JUN-18 14:15:00 (CST-6)
Location: BENA
Magnitude: 1.00 
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Public

Cherry tomato-sized hail was observed at a resort on the south shore of Lake Winnibigoshish.

Funnel Cloud in ST. LOUIS, MINNESOTA
From 28-JUN-18 12:56:00 to 28-JUN-18 12:56:00 (CST-6)
Location: ADOLPH
Property damage: 0.00K
Crop damage: 0.00K
Reported by: State Official

Multiple 911 calls were received for a funnel cloud near the 4000 block of Solway Road.