The early morning hours of Friday, June 29th, remained warm and muggy. Just after midnight, temperatures were still in the 70s with dew points around 70. A line of thunderstorms moved into the Devils Lake area around 2 am CDT. This line of storms had several bowing segments, which are indicative of strong winds. The most obvious bowing segment between highway 2 and Interstate 94, where the most amount of damage occurred. The main bowing segment exited into north central Minnesota around 6 am CDT. Well behind the bowing thunderstorm complex, a mesoscale convective vortex (MCV) formed, and produced another round of widespread damaging winds.

Thunderstorm Wind in RAMSEY, NORTH DAKOTA
From 29-JUN-18 02:05:00 to 29-JUN-18 02:05:00 (CST-6)
Location: LAKEWOOD PARK
Magnitude: 55.00 EG
Reported by: NWS Storm Survey

Tree damage was reported in the Woodlawn and Lakeview areas.

Thunderstorm Wind in BENSON, NORTH DAKOTA
From 29-JUN-18 02:15:00 to 29-JUN-18 02:15:00 (CST-6)
Location: TOKIO
Magnitude: 65.00 EG
Reported by: Other Federal Agency

Quite a bit of tree damage was reported.

Thunderstorm Wind in GRIGGS, NORTH DAKOTA
From 29-JUN-18 02:20:00 to 29-JUN-18 02:20:00 (CST-6)
Location: BINFORD
Magnitude: 55.00 EG
Reported by: Public

Fairly large tree branches were blown down.

Thunderstorm Wind in GRIGGS, NORTH DAKOTA
From 29-JUN-18 02:21:00 to 29-JUN-18 02:21:00 (CST-6)
Location: JESSIE
Magnitude: 83.00 MG
Reported by: Public

The wind gust was measured by a personal weather station.

Thunderstorm Wind in NELSON, NORTH DAKOTA
From 29-JUN-18 02:30:00 to 29-JUN-18 02:30:00 (CST-6)
Location: MICHIGAN CITY
Magnitude: 55.00 EG
Reported by: COOP Observer

Large tree branches were blown down around town.

Thunderstorm Wind in BARNES, NORTH DAKOTA
From 29-JUN-18 02:33:00 to 29-JUN-18 02:33:00 (CST-6)
Location: VALLEY CITY
Magnitude: 55.00 EG
Reported by: Public

Tree limbs and several power poles were broken.

Thunderstorm Wind in NELSON, NORTH DAKOTA
From 29-JUN-18 02:34:00 to 29-JUN-18 02:34:00 (CST-6)
Location: MC VILLE
Magnitude: 83.00 EG
Reported by: COOP Observer

A grain bin was blown in and there was significant tree damage.

Thunderstorm Wind in NELSON, NORTH DAKOTA
From 29-JUN-18 02:38:00 to 29-JUN-18 02:38:00 (CST-6)
Location: LAKOTA
Magnitude: 70.00 EG
Reported by: Social Media

Trees were blown down and there was a lot of roof damage due to falling trees.

Thunderstorm Wind in NELSON, NORTH DAKOTA
From 29-JUN-18 02:40:00 to 29-JUN-18 02:40:00 (CST-6)
Location: ANETA
Magnitude: 60.00 EG
Reported by: NWS Storm Survey

Four to six inch diameter tree limbs were blown down.

Thunderstorm Wind in RAMSEY, NORTH DAKOTA
From 29-JUN-18 02:40:00 to 29-JUN-18 02:40:00 (CST-6)
Location: SOUTHAM
Magnitude: 60.00 EG
Reported by: Public

Tree and roof damage was reported.

Thunderstorm Wind in STEELE, NORTH DAKOTA
From 29-JUN-18 02:44:00 to 29-JUN-18 02:44:00 (CST-6)
Location: SHERBROOKE
Magnitude: 70.00 EG
Reported by: Emergency Manager

Several large trees were blown down, four pontoons were blown off their lifts, and several docks were smashed by the strong winds.

Thunderstorm Wind in NELSON, NORTH DAKOTA
From 29-JUN-18 02:45:00 to 29-JUN-18 02:45:00 (CST-6)
Location: MICHIGAN CITY
Magnitude: 65.00 EG
Reported by: Social Media

A tree was snapped and a trampoline was damaged.

Thunderstorm Wind in STEELE, NORTH DAKOTA
From 29-JUN-18 02:45:00 to 29-JUN-18 02:45:00 (CST-6)
Location: SHERBROOKE
Magnitude: 55.00 MG
Reported by: Public

The wind gust was measured by a personal weather station.

Thunderstorm Wind in SARGENT, NORTH DAKOTA
From 29-JUN-18 02:50:00 to 29-JUN-18 02:50:00 (CST-6)
Location: STIRUM
Magnitude: 55.00 EG
Reported by: Social Media

Four inch diameter tree limbs were blown down.

Thunderstorm Wind in TRAILL, NORTH DAKOTA
From 29-JUN-18 02:51:00 to 29-JUN-18 02:51:00 (CST-6)
Location: PORTLAND
Magnitude: 55.00 EG
Reported by: Public

Tree damage was reported.

Thunderstorm Wind in GRAND FORKS, NORTH DAKOTA
From 29-JUN-18 02:52:00 to 29-JUN-18 02:57:00 (CST-6)
Location: NORTHWOOD
Magnitude: 91.00 EG
Reported by: NWS Storm Survey

A bowing section of a squall line cut across east central Avon Township. Numerous large trees were snapped along its path.

Tornado in GRAND FORKS, NORTH DAKOTA
From 29-JUN-18 02:55:00 to 29-JUN-18 02:58:00 (CST-6)
Location: KEMPTON
Tornado F-scale: EF1
Reported by: NWS Storm Survey

A brief tornado initiated to the north of a bowing section of squall line as it moved into Avon Township. Extreme tree damage was noted along its path and three cattle trailers were overthrown at a farmstead. Peak winds were estimated at 95 mph.

Thunderstorm Wind in RANSOM, NORTH DAKOTA
From 29-JUN-18 02:58:00 to 29-JUN-18 02:58:00 (CST-6)
Location: LISBON
Magnitude: 55.00 EG
Reported by: Broadcast Media

A large tree branch was blown down.

Thunderstorm Wind in GRAND FORKS, NORTH DAKOTA
From 29-JUN-18 02:58:00 to 29-JUN-18 02:58:00 (CST-6)
Location: SHAWNEE
Magnitude: 61.00 MG
Reported by: Public

The wind gust was measured by a personal weather station.

Thunderstorm Wind in GRAND FORKS, NORTH DAKOTA
From 29-JUN-18 03:00:00 to 29-JUN-18 03:00:00 (CST-6)
Location: (RDR)GRAND FORKS AFB
Magnitude: 70.00 EG
Reported by: Social Media

Significant tree damage was reported, with one tree falling into a house. Brick structures were damaged as well as several street signs.

Thunderstorm Wind in NELSON, NORTH DAKOTA
From 29-JUN-18 03:00:00 to 29-JUN-18 03:00:00 (CST-6)
Location: LAKOTA
Magnitude: 60.00 EG
Reported by: Social Media

Large tree branches were blown down.

Thunderstorm Wind in RANSOM, NORTH DAKOTA
From 29-JUN-18 03:00:00 to 29-JUN-18 03:00:00 (CST-6)
Location: ENDERLIN ARPT
Magnitude: 70.00 EG
Reported by: COOP Observer

Large trees were snapped.

Thunderstorm Wind in TRAILL, NORTH DAKOTA
From 29-JUN-18 03:00:00 to 29-JUN-18 03:00:00 (CST-6)
Location: HILLSBORO
Magnitude: 65.00 EG
Reported by: Social Media

Several trees were blown down.

Thunderstorm Wind in GRAND FORKS, NORTH DAKOTA
From 29-JUN-18 03:02:00 to 29-JUN-18 03:02:00 (CST-6)
Location: EDISONS
Magnitude: 60.00 EG
Reported by: Social Media

Six inch diameter tree branches were knocked down by the strong wind.

Thunderstorm Wind in GRAND FORKS, NORTH DAKOTA
From 29-JUN-18 03:04:00 to 29-JUN-18 03:04:00 (CST-6)
Location: EMERADO
Magnitude: 65.00 EG
Reported by: Broadcast Media

A large tree was uprooted.

Thunderstorm Wind in GRAND FORKS, NORTH DAKOTA
From 29-JUN-18 03:06:00 to 29-JUN-18 03:06:00 (CST-6)
Location: OJATA
Magnitude: 75.00 EG
Reported by: Other Federal Agency

Many trees were toppled in shelterbelts east of the Grand Forks Air Force Base exit along highway 2. At least one wooden power pole was snapped in a farm yard.

Thunderstorm Wind in EDDY, NORTH DAKOTA
From 29-JUN-18 03:07:00 to 29-JUN-18 03:07:00 (CST-6)
Location: HAMAR
Magnitude: 50.00 MG
Reported by: Mesonet

The wind gust was measured by a NDAWN mesonet wind sensor.

Thunderstorm Wind in GRAND FORKS, NORTH DAKOTA
From 29-JUN-18 03:08:00 to 29-JUN-18 03:08:00 (CST-6)
Location: (RDR)GRAND FORKS AFB
Magnitude: 54.00 MG
Reported by: ASOS

The strong wind toppled trees and signs. Large branches were also pushed into houses by the strong wind.

Thunderstorm Wind in GRAND FORKS, NORTH DAKOTA
From 29-JUN-18 03:09:00 to 29-JUN-18 03:09:00 (CST-6)
Location: MERRIFIELD
Magnitude: 83.00 EG
Reported by: Public

Four large grain bins were blown down and off their foundations at Drees Farming, near Merrifield. A sprayer was also wrapped around a grain bin. Debris from the grain bins was spread for several miles eastward. Numerous trees were snapped or uprooted between Merrifield and the Kings Walk Golf Course on the south side of Grand Forks.

Thunderstorm Wind in GRAND FORKS, NORTH DAKOTA
From 29-JUN-18 03:09:00 to 29-JUN-18 03:09:00 (CST-6)
Location: MEKINOCK
Magnitude: 70.00 EG
Reported by: Social Media

A large tree was snapped.

Thunderstorm Wind in TRAILL, NORTH DAKOTA
From 29-JUN-18 03:13:00 to 29-JUN-18 03:13:00 (CST-6)
Location: ALTON
Magnitude: 60.00 EG
Reported by: NWS Employee

A tree was blown down near mile marker 100 along Interstate 29.

Thunderstorm Wind in GRAND FORKS, NORTH DAKOTA
From 29-JUN-18 03:13:00 to 29-JUN-18 03:13:00 (CST-6)
Location: (GFK)GRAND FORKS INT
Magnitude: 66.00 MG
Reported by: ASOS

The wind gust was measured by the ASOS at the Grand Forks airport.

Thunderstorm Wind in GRAND FORKS, NORTH DAKOTA
From 29-JUN-18 03:15:00 to 29-JUN-18 03:15:00 (CST-6)
Location: HOLMES
Magnitude: 65.00 EG
Reported by: Social Media

Extensive tree damage was reported.

Thunderstorm Wind in GRAND FORKS, NORTH DAKOTA
From 29-JUN-18 03:15:00 to 29-JUN-18 03:15:00 (CST-6)
Location: GRAND FORKS
Magnitude: 60.00 EG
Reported by: Social Media

A large tree was blown down.

Thunderstorm Wind in GRAND FORKS, NORTH DAKOTA
From 29-JUN-18 03:15:00 to 29-JUN-18 03:15:00 (CST-6)
Location: GRAND FORKS
Magnitude: 55.00 EG
Reported by: Social Media

Tree damage was reported in south Grand Forks.

Thunderstorm Wind in GRAND FORKS, NORTH DAKOTA
From 29-JUN-18 03:17:00 to 29-JUN-18 03:17:00 (CST-6)
Location: (GFK)GRAND FORKS INT
Magnitude: 70.00 EG
Reported by: Public

Small trees were snapped in a yard and shingles, siding, and gutters on a house were damaged.

Thunderstorm Wind in TRAILL, NORTH DAKOTA
From 29-JUN-18 03:30:00 to 29-JUN-18 03:30:00 (CST-6)
Location: HATTON ARPT
Magnitude: 70.00 EG
Reported by: Social Media

Trees were blown down along highway 15.

Thunderstorm Wind in CASS, NORTH DAKOTA
From 29-JUN-18 03:40:00 to 29-JUN-18 03:40:00 (CST-6)
Location: WILD RICE
Magnitude: 75.00 EG
Reported by: Broadcast Media

The Davies High School pool was damaged. Benches with cement footings were overturned, large umbrellas destroyed, and light fixtures broken.

Thunderstorm Wind in GRAND FORKS, NORTH DAKOTA
From 29-JUN-18 03:49:00 to 29-JUN-18 03:49:00 (CST-6)
Location: GRAND FORKS
Magnitude: 55.00 EG
Reported by: Social Media

A portion of a fence was blown down in south Grand Forks.

Thunderstorm Wind in BENSON, NORTH DAKOTA
From 29-JUN-18 01:35:00 to 29-JUN-18 01:35:00 (CST-6)
Location: LEEDS
Magnitude: 50.00 EG
Reported by: Public

Three to five inch diameter tree branches were blown down.

Thunderstorm Wind in BENSON, NORTH DAKOTA
From 29-JUN-18 01:37:00 to 29-JUN-18 01:37:00 (CST-6)
Location: OBERON
Magnitude: 70.00 EG
Reported by: Public

Tree and roof damage was reported in Oberon. A few cottonwood trees were blown down in shelterbelts across Oberon Township.

Thunderstorm Wind in EDDY, NORTH DAKOTA
From 29-JUN-18 01:50:00 to 29-JUN-18 01:50:00 (CST-6)
Location: NEW ROCKFORD ARPT
Magnitude: 55.00 EG
Reported by: Trained Spotter

Tree damage was reported at the golf course.

Thunderstorm Wind in TOWNER, NORTH DAKOTA
From 29-JUN-18 01:55:00 to 29-JUN-18 01:55:00 (CST-6)
Location: CANDO MUNI ARPT
Magnitude: 50.00 MG
Reported by: AWOS

The wind gust was measured at the Cando airport.