The Boundary Waters–Canadian Derecho (also called the Boundary Waters Blowdown) was an international

derecho A ''derecho'' (, from , 'straight') is a widespread, long-lived, straight-line wind storm that is associated with a fast-moving group of Severe weather#Categories, severe thunderstorms known as a mesoscale convective system. Derechos cause Bea ...

that occurred during the afternoon and evening of July 4 and the early morning of July 5, 1999. It traveled and lasted 22 hours.

Storm path

North Dakota

In the pre-dawn of July 4, a band of

thunderstorms A thunderstorm, also known as an electrical storm or a lightning storm, is a storm characterized by the presence of lightning and its acoustic effect on the Earth's atmosphere, known as thunder. Relatively weak thunderstorms are som ...

developed over far eastern

North Dakota North Dakota ( ) is a U.S. state in the Upper Midwest, named after the indigenous Dakota people, Dakota and Sioux peoples. It is bordered by the Canadian provinces of Saskatchewan and Manitoba to the north and by the U.S. states of Minneso ...

Hector International Airport Hector International Airport is a civil-military public airport three miles (5 km) northwest of Fargo, in Cass County, North Dakota, United States. The busiest airport in North Dakota, it is owned by the City of Fargo Municipal Airport A ...

in northwest Fargo recorded winds in excess of 58 mph (95 km/h) for 40 minutes and a maximum wind gust of . Many planes were damaged or overturned. The hangars suffered damage as well. The worst damage occurred farther south in West Fargo, North Dakota and in south central Fargo, North Dakota. Wind gusts in these areas were estimated at as high as . The storm caused $85 million in damage (1999 dollars) in the Fargo metropolitan area. Over 40,000 people were without power. Cars were overturned, roofs were severely damaged, and power poles were blown down.

Minnesota

The derecho moved into

Minnesota Minnesota ( ) is a U.S. state, state in the Upper Midwestern region of the United States. It is bordered by the Canadian provinces of Manitoba and Ontario to the north and east and by the U.S. states of Wisconsin to the east, Iowa to the so ...

and caused massive damage in

Cass Cass may refer to: People and fictional characters * Cass (surname), a list of people * Cass (given name), a list of people and fictional characters * Big Cass, ring name of wrestler William Morrissey * Cass, in British band Skunk Anansie * Cass, ...

, Itasca, and Aitkin Counties, at around $3 million. A semi-trailer truck was blown over on U.S. Route 53 near

Canyon A canyon (; archaic British English spelling: ''cañon''), gorge or chasm, is a deep cleft between escarpments or cliffs resulting from weathering and the erosive activity of a river over geologic time scales. Rivers have a natural tendency t ...

. One person was killed and 60 were injured as the derecho passed through the

Boundary Waters Canoe Area Wilderness The Boundary Waters Canoe Area Wilderness (BWCAW or BWCA) comprises of pristine forests, glacial lakes, and streams in the Superior National Forest. Located entirely within the U.S. state of Minnesota at the Boundary Waters, the wilderness are ...

(BWCAW) and

Superior National Forest The Superior National Forest, part of the United States National Forest system, is located in the Arrowhead Region of the U.S. state, state of Minnesota between the Canada–United States border and the North Shore (Lake Superior), north shore o ...

. People were there to enjoy canoeing and other recreation for the

Independence Day An independence day is an annual event memorialization, commemorating the anniversary of a nation's independence or Sovereign state, statehood, usually after ceasing to be a group or part of another nation or state, or after the end of a milit ...

weekend. Straight line winds in excess of 90 mph (145 km/h) uprooted and snapped off trees in over 370,000 acres (1,500 km²) of the 1 million acre (4,000 km²) wilderness area. In total, more than 477,000 acres (1,930 km²) of forest was affected in the

in a swath 30 miles (48.3 km) long and 4 to 12 miles (6.4 to 19.3 km) wide. It is estimated that 25 million trees were blown down in the BWCAW.

Ontario

The derecho brought more damage when it crossed the border into

Ontario Ontario is the southernmost Provinces and territories of Canada, province of Canada. Located in Central Canada, Ontario is the Population of Canada by province and territory, country's most populous province. As of the 2021 Canadian census, it ...

during the early afternoon of July 4. At its peak near

Thunder Bay Thunder Bay is a city in and the seat of Thunder Bay District, Ontario, Canada. It is the most populous municipality in Northwestern Ontario and the second most populous (after Greater Sudbury) municipality in Northern Ontario. Its population i ...

, the winds were estimated to have been much stronger, around 100 mph (160 km/h) and it spawned some small

tornadoes A tornado is a violently rotating column of air that is in contact with the surface of Earth and a cumulonimbus cloud or, in rare cases, the base of a cumulus cloud. It is often referred to as a twister, whirlwind or cyclone, although the ...

. One small sailboat was overturned and two people were thrown into the cold waters of

Lake Superior Lake Superior is the largest freshwater lake in the world by surface areaThe Caspian Sea is the largest lake, but is saline, not freshwater. Lake Michigan–Huron has a larger combined surface area than Superior, but is normally considered tw ...

. They were rescued by a nearby boater. The storm carved a path of destruction into the sparsely populated forested areas of northern Ontario. The

Canadian Pacific The Canadian Pacific Railway () , also known simply as CPR or Canadian Pacific and formerly as CP Rail (1968–1996), is a Canadian Class I railway incorporated in 1881. The railway is owned by Canadian Pacific Kansas City, Canadian Pacific Ka ...

track between White River and Chapleau in northeastern Ontario was put out of service by fallen trees. Significant tree and property damage was recorded in

Timmins Timmins ( ) is a city in northeastern Ontario, Canada, located on the Mattagami River. The city is the fourth-largest city in the Northeastern Ontario region with a population of 41,145 at the 2021 Canadian census and an estimated population of ...

Quebec

Boundery waters Canadian Derecho radar image

As it raced eastward at 62 mph (100 km/h), the system entered into western

Quebec Quebec is Canada's List of Canadian provinces and territories by area, largest province by area. Located in Central Canada, the province shares borders with the provinces of Ontario to the west, Newfoundland and Labrador to the northeast, ...

in the Témiscamingue region around 11:00 p.m. A gust of 65 mph (102 km/h) was reported at the automatic station of Angliers. There was also a tremendous amount of lightning associated with this derecho, with around 6,000 lightning strikes per hour. Another person in this derecho was killed at

Val-des-Lacs Val-des-Lacs (; meaning "Valley of Lakes") is a municipality in the Laurentides region of Quebec, Canada, part of the Les Laurentides Regional County Municipality. Demographics Population trend: * Population in 2011: 721 (2006 to 2011 population ...

(V on the map) when a tree fell on the victim. A woman was injured when a tree crushed her car. After narrowly missing the

Ottawa Ottawa is the capital city of Canada. It is located in the southern Ontario, southern portion of the province of Ontario, at the confluence of the Ottawa River and the Rideau River. Ottawa borders Gatineau, Gatineau, Quebec, and forms the cor ...

area, the storm moved quickly into

Montreal Montreal is the List of towns in Quebec, largest city in the Provinces and territories of Canada, province of Quebec, the List of the largest municipalities in Canada by population, second-largest in Canada, and the List of North American cit ...

(M on the map) around 3:00 a.m. heading southeastward toward Maine. Much damage was recorded in the Metropolitan area but the worst affected area of Quebec was farther along its path near Sherbrooke (S on the map) in the

Eastern Townships The Eastern Townships (, ) is a historical administrative region in southeastern Quebec, Canada. It lies between the Great Lakes–St. Lawrence Lowlands, St. Lawrence Lowlands and the American border, and extends from Granby, Quebec, Granby in ...

where a church was badly damaged, farm buildings were damaged and 2,000 trees were felled. Hydro-Québec reported that over 600,000 people lost power; some were without power for over a week.

New England

The storm continued southeast and caused more damage in

New Hampshire New Hampshire ( ) is a U.S. state, state in the New England region of the Northeastern United States. It borders Massachusetts to the south, Vermont to the west, Maine and the Gulf of Maine to the east, and the Canadian province of Quebec t ...

and

Vermont Vermont () is a U.S. state, state in the New England region of the Northeastern United States. It borders Massachusetts to the south, New Hampshire to the east, New York (state), New York to the west, and the Provinces and territories of Ca ...

, killing one more person, before finally dissipating in

Maine Maine ( ) is a U.S. state, state in the New England region of the United States, and the northeasternmost state in the Contiguous United States. It borders New Hampshire to the west, the Gulf of Maine to the southeast, and the Provinces and ...

after 5:00 a.m. on July 5.

Aftermath

The Boundary Waters – Canadian Derecho is one of the farthest north "progressive" derechos to have ever been recorded. The derecho caused well over $100 million in damage, killed 4 persons and injured 70. Over 700,000 homes and businesses lost power from the event.

References

{{DEFAULTSORT:Boundary Waters - Canadian derecho 1999 meteorology 1999 natural disasters in the United States Derechos in the United States Derechos in Canada Natural disasters in North Dakota Natural disasters in Minnesota Natural disasters in Ontario Natural disasters in Quebec 1999 in Minnesota July 1999 in North America 1999 disasters in Canada