Early in the afternoon of the 17th, one supercell tracked across extreme southwest Benson county, down through western Eddy county, and into Griggs county. This cell maintained a very slow southeast movement along its entire track. The supercell fed off an extremely unstable atmosphere, with surface temperatures in the 80s and 90s and dew point readings in the mid to upper 70s. By late afternoon into the early evening, more storms broke out along and south of the Interstate 94 corridor.

Hail in EDDY, NORTH DAKOTA
From 17-JUL-11 12:15:00 to 17-JUL-11 12:15:00 (CST-6)
Location: NEW ROCKFORD
Magnitude: 2.00 
Reported by: Broadcast Media

Tornado in CASS, NORTH DAKOTA
From 17-JUL-11 16:23:00 to 17-JUL-11 16:25:00 (CST-6)
Location: AYR
Tornado F-scale: EF0
Reported by: NWS Storm Survey

The tornado touchdown was visible from near Ayr. Tree branches and limbs were broken down along a narrow path in two shelterbelts. Two smaller trees were snapped and thrown about in a farm yard. Peak winds were estimated at 80 mph.

Hail in CASS, NORTH DAKOTA
From 17-JUL-11 16:11:00 to 17-JUL-11 16:11:00 (CST-6)
Location: NOLAN
Magnitude: 1.75 
Reported by: Law Enforcement

Funnel Cloud in CASS, NORTH DAKOTA
From 17-JUL-11 16:35:00 to 17-JUL-11 16:35:00 (CST-6)
Location: MAGNOLIA
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Broadcast Media

A well developed wall cloud with a weak funnel were reported.

Thunderstorm Wind in SARGENT, NORTH DAKOTA
From 17-JUL-11 18:32:00 to 17-JUL-11 18:32:00 (CST-6)
Location: STIRUM
Magnitude: 52.00 MG
Reported by: Trained Spotter

Thunderstorm Wind in SARGENT, NORTH DAKOTA
From 17-JUL-11 18:47:00 to 17-JUL-11 18:47:00 (CST-6)
Location: GWINNER ARPT
Magnitude: 63.00 MG
Reported by: Trained Spotter

Very high winds were reported east of Gwinner along with near zero visibility due to wind and rain. The highway had several tree branches across it.

Thunderstorm Wind in SARGENT, NORTH DAKOTA
From 17-JUL-11 19:10:00 to 17-JUL-11 19:10:00 (CST-6)
Location: RANSOM
Magnitude: 50.00 EG
Reported by: Trained Spotter

A four to six inch diameter birch tree, roughly 40 feet tall, was blown down by the strong winds.

Thunderstorm Wind in RICHLAND, NORTH DAKOTA
From 17-JUL-11 19:12:00 to 17-JUL-11 19:12:00 (CST-6)
Location: LIDGERWOOD
Magnitude: 52.00 EG
Reported by: COOP Observer

Numerous 4 inch diameter tree branches were blown down.

Thunderstorm Wind in RICHLAND, NORTH DAKOTA
From 17-JUL-11 19:46:00 to 17-JUL-11 19:46:00 (CST-6)
Location: DWIGHT
Magnitude: 54.00 MG
Reported by: Mesonet

The winds were measured by a ND DOT RWIS sensor along highway 13.

Thunderstorm Wind in RICHLAND, NORTH DAKOTA
From 17-JUL-11 19:55:00 to 17-JUL-11 19:55:00 (CST-6)
Location: WAHPETON ARPT
Magnitude: 50.00 MG
Reported by: AWOS

The wind gust was measured at the Wahpeton airport.

Hail in BENSON, NORTH DAKOTA
From 17-JUL-11 11:10:00 to 17-JUL-11 11:10:00 (CST-6)
Location: MADDOCK RICES ARPT
Magnitude: 0.88 
Reported by: Public

Dime to nickel sized hail fell with very heavy rain.

Hail in EDDY, NORTH DAKOTA
From 17-JUL-11 11:55:00 to 17-JUL-11 11:55:00 (CST-6)
Location: NEW ROCKFORD
Magnitude: 1.00 
Reported by: Fire Department/Rescue

Hail in EDDY, NORTH DAKOTA
From 17-JUL-11 12:05:00 to 17-JUL-11 12:05:00 (CST-6)
Location: SHEYENNE
Magnitude: 0.75 
Reported by: Law Enforcement

Thunderstorm Wind in EDDY, NORTH DAKOTA
From 17-JUL-11 12:07:00 to 17-JUL-11 12:07:00 (CST-6)
Location: NEW ROCKFORD
Magnitude: 65.00 EG
Reported by: NWS Employee

Two power poles were snapped along United States highway 281.

Thunderstorm Wind in EDDY, NORTH DAKOTA
From 17-JUL-11 12:07:00 to 17-JUL-11 12:07:00 (CST-6)
Location: NEW ROCKFORD
Magnitude: 60.00 EG
Reported by: Fire Department/Rescue

High winds in town blew down trees with some street flooding also reported.

Tornado in GRIGGS, NORTH DAKOTA
From 17-JUL-11 13:35:00 to 17-JUL-11 13:50:00 (CST-6)
Location: SUTTON
Tornado F-scale: EF0
Reported by: NWS Storm Survey

This tornado tracked intermittently along the path and knocked down several trees in shelterbelts. Peak winds were estimated at 85 mph.

Tornado in GRIGGS, NORTH DAKOTA
From 17-JUL-11 14:16:00 to 17-JUL-11 14:18:00 (CST-6)
Location: HANNAFORD
Tornado F-scale: EF0
Reported by: Storm Chaser

Trees and limbs were blown down along the tornado path. Peak winds were estimated at 80 mph.

Hail in BARNES, NORTH DAKOTA
From 17-JUL-11 15:15:00 to 17-JUL-11 15:15:00 (CST-6)
Location: PILLSBURY
Magnitude: 2.75 
Reported by: Public

Hail in CASS, NORTH DAKOTA
From 17-JUL-11 15:36:00 to 17-JUL-11 15:36:00 (CST-6)
Location: PAGE
Magnitude: 1.75 
Reported by: Broadcast Media

Hail in CASS, NORTH DAKOTA
From 17-JUL-11 16:10:00 to 17-JUL-11 16:10:00 (CST-6)
Location: MASON
Magnitude: 1.50 
Reported by: Storm Chaser

Hail in BENSON, NORTH DAKOTA
From 17-JUL-11 11:15:00 to 17-JUL-11 11:15:00 (CST-6)
Location: MADDOCK RICES ARPT
Magnitude: 1.00 
Crop damage: 150.00K
Reported by: Public

Dime to quarter sized hail driven by very strong winds produced widespread crop damage near the Wells county line.

Hail in EDDY, NORTH DAKOTA
From 17-JUL-11 12:06:00 to 17-JUL-11 12:06:00 (CST-6)
Location: NEW ROCKFORD
Magnitude: 1.75 
Property damage: 100.00K
Crop damage: 100.00K
Reported by: Law Enforcement

Hail moved into the town of New Rockford where shingles, roofing, and vehicles received some damages.

Tornado in EDDY, NORTH DAKOTA
From 17-JUL-11 12:09:00 to 17-JUL-11 12:12:00 (CST-6)
Location: NEW ROCKFORD
Tornado F-scale: EF1
Property damage: 10.00K
Crop damage: 10.00K
Reported by: NWS Storm Survey

The tornado broke down two power poles along the west side of highway 281 and severely damaged several trees in a shelterbelt east of highway 281. Peak winds were estimated at 105 mph.

Thunderstorm Wind in RICHLAND, NORTH DAKOTA
From 17-JUL-11 19:15:00 to 17-JUL-11 19:16:00 (CST-6)
Location: LIDGERWOOD
Magnitude: 60.00 EG
Property damage: 20.00K
Reported by: COOP Observer

A large tree was blown onto a house. Other trees were uprooted.

Funnel Cloud in CASS, NORTH DAKOTA
From 17-JUL-11 16:24:00 to 17-JUL-11 16:24:00 (CST-6)
Location: AYR
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Trained Spotter

A sequence of two short lived funnels was viewed from near Wheatland. The funnels appeared to come down about one-third of the way from the cloud and then go back up again. From this distance, these funnels likely produced the brief tornado touchdown three miles south of Ayr.

Hail in CASS, NORTH DAKOTA
From 17-JUL-11 16:25:00 to 17-JUL-11 16:30:00 (CST-6)
Location: ABSARAKA
Magnitude: 1.50 
Reported by: Broadcast Media