On the morning of July 21st, a thunderstorm just north of the Canadian border moved southeast into Cavalier County, North Dakota, where it dropped large hail. This storm weakened for a few hours, but remained intact. The same storm re-intensified by mid afternoon over eastern Marshall County, Minnesota, and remained very strong until it reached the town of Saum, in Beltrami County, Minnesota. Meanwhile, temperatures by the afternoon of the 21st rose into the lower 90s, with dew points in the mid 60s to lower 70s. More strong thunderstorms moved into the Cooperstown, North Dakota, area, and tracked to the east-southeast. Then, during the early evening, a line of strong storms consolidated from near Bemidji to just east of Moorhead, Minnesota. This line of storms held together as it moved to the east-southeast. By late evening, more strong storms moved into the Devils Lake region, still tracking to the east-southeast. This area of storms continued to hold together, flaring up near Hunter, North Dakota, and near Pelican Rapids, Minnesota, where it produced several reports of strong winds.

Funnel Cloud in BENSON, NORTH DAKOTA
From 21-JUL-17 22:25:00 to 21-JUL-17 22:25:00 (CST-6)
Location: COMSTOCK
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Law Enforcement

The funnel was viewed from about five miles north of Minnewauken, looking west.

Hail in CAVALIER, NORTH DAKOTA
From 21-JUL-17 09:05:00 to 21-JUL-17 09:05:00 (CST-6)
Location: HANNAH
Magnitude: 1.00 
Reported by: Other Federal Agency

Thunderstorm Wind in GRIGGS, NORTH DAKOTA
From 21-JUL-17 14:42:00 to 21-JUL-17 14:42:00 (CST-6)
Location: COOPERSTOWN
Magnitude: 55.00 EG
Reported by: Public

A corn field was shredded by hail and strong winds.

Thunderstorm Wind in GRIGGS, NORTH DAKOTA
From 21-JUL-17 14:51:00 to 21-JUL-17 14:51:00 (CST-6)
Location: COOPERSTOWN
Magnitude: 50.00 MG
Reported by: Mesonet

The wind gust was measured by a NDAWN station.

Hail in CASS, NORTH DAKOTA
From 21-JUL-17 16:00:00 to 21-JUL-17 16:00:00 (CST-6)
Location: CASSELTON
Magnitude: 0.88 
Reported by: Public

Dime to nickel sized hail fell.

Hail in RICHLAND, NORTH DAKOTA
From 21-JUL-17 17:10:00 to 21-JUL-17 17:10:00 (CST-6)
Location: STILES
Magnitude: 1.00 
Reported by: Public

The hail was mostly pea to dime sized.

Hail in BENSON, NORTH DAKOTA
From 21-JUL-17 22:00:00 to 21-JUL-17 22:00:00 (CST-6)
Location: FILLMORE
Magnitude: 1.00 
Reported by: Public

Hail in BENSON, NORTH DAKOTA
From 21-JUL-17 22:18:00 to 21-JUL-17 22:18:00 (CST-6)
Location: HARLOW
Magnitude: 1.25 
Reported by: Public

The hail ranged in size from pea on up.

Thunderstorm Wind in CASS, NORTH DAKOTA
From 22-JUL-17 01:42:00 to 22-JUL-17 01:42:00 (CST-6)
Location: HUNTER
Magnitude: 52.00 MG
Reported by: Public

The wind gust was measured by a personal weather station.

Thunderstorm Wind in STEELE, NORTH DAKOTA
From 21-JUL-17 15:15:00 to 21-JUL-17 15:15:00 (CST-6)
Location: BLABON
Magnitude: 51.00 MG
Reported by: Mesonet

The wind gust was measured by a personal weather station.

Hail in BENSON, NORTH DAKOTA
From 21-JUL-17 22:33:00 to 21-JUL-17 22:33:00 (CST-6)
Location: TILDEN
Magnitude: 1.50 
Reported by: Public

The large hail was accompanied by very strong winds, which were estimated to be 50 mph or greater.

Hail in EDDY, NORTH DAKOTA
From 21-JUL-17 23:46:00 to 21-JUL-17 23:49:00 (CST-6)
Location: HAMAR
Magnitude: 1.25 
Reported by: Public

Dime to half dollar sized hail fell.

Hail in RANSOM, NORTH DAKOTA
From 22-JUL-17 02:25:00 to 22-JUL-17 02:25:00 (CST-6)
Location: BUTTZVILLE
Magnitude: 1.25 
Reported by: Public

The large hail was accompanied by a strong wind, which blew down some small branches in a farm yard.