EF4 Tornado — Grand Forks, North Dakota

2007-08-26 · near Northwood, Grand Forks, North Dakota

Event narrative

The tornado touched down about 2 miles west-southwest of Northwood. The tornado crossed the Goose River about a mile west-southwest of the Northwood airport and left a 200 yard wide stretch of downed trees in its wake. By the time it hit the airport, the ground track was one-third of a mile wide and growing wider. At this point the tornado was still visible outside the increasingly heavy rain.

The tornado reached an incredible width of eight-tenths of a mile as it pushed through Northwood to the east-northeast. At this point it had multiple vortices embedded in the overall wedge shaped tornado. The strongest of these vortices appears to have scoured the ground and left broad circulation patterns of debris in the overall damage and debris field. Around this time the tornado likely became wrapped in heavy rain and would have been difficult to observe from a distance. The most extreme damage appeared to be in the northeast corner of the community.

Northwood, in southwest Grand Forks County, had a population of about 1000 people. 90 percent of the roughly 460 homes were damaged. One death occurred in a mobile home, with 18 other injuries reported. The death occurred in a trailer park on the north edge of town, where 19 total units were demolished.

Just to the east of the trailer park, in the area that sustained the extreme damage, three businesses were hit particularly hard. An agricultural company, the towns largest employer, had its buildings heavily damaged. A nearby construction company lost two large steel buildings and other equipment. Steel beams from the two steel buildings were twisted and tossed nearby. Finally, a car dealership lost 15 to 20 vehicles from its parking lot along highway 15. Many of these vehicles were damaged beyond recognition and tossed into nearby fields. One corn field to the north of highway 15 (across from the 3 businesses on the northeast side of town) had it stalks snapped off several inches from the root bases, with pieces of husked corn laying around.

Hangers and airplanes were also damaged at the airport. The local health center, school, supermarket, and grain elevator were damaged. Near the elevator, several rail cars were knocked off the tracks. Hundreds of trees were snapped, uprooted, or damaged. Power was also knocked out to many customers, but eventually was turned off (for safety reasons) to the entire town. A total of about 2600 truckloads of debris were hauled to the town landfill. In the days following the tornado, a Presidential Disaster Declaration was granted.

Wider weather episode

A cold front moved across North Dakota on the 26th, with a hot and humid airmass in place ahead of the front. At 6 pm CST, a surface low was located over southern Manitoba (Canada), just north of Pembina, ND. The cold front stretched to the southwest, back toward Devils Lake (ND) and Bismarck (ND). Ahead of the cold front, temperatures ranged in the low to mid 80s with dew points around 70F. Behind the front, temperatures did not cool significantly, but dew points dropped to the mid 40s. Thunderstorms began to form along and ahead of the cold front by early evening (from northeast ND into south central ND), eventually crossing into northwest Minnesota several hours later. Eight distinct tornadoes occurred over northeast North Dakota and northwest Minnesota during this event.

View location on OpenStreetMap → (47.7189, -97.6097)

Source: NOAA Storm Events Database, event_id 48727. Narrative written by the NWS forecast office that issued the report.