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January 1998 North American ice storm
The North American Ice Storm of 1998 (also known as the Great Ice Storm of 1998 or the January Ice Storm) was a massive combination of five smaller successive ice storms in January 1998 that struck a relatively narrow swath of land from eastern Ontario to southern Quebec, New Brunswick and Nova Scotia in Canada, and bordering areas from northern New York to central Maine in the United States. It caused massive damage to trees and electrical infrastructure throughout the area, leading to widespread long-term power outages. Millions were left in the dark for periods varying from days to several weeks, and in some instances, months. It led to 34 fatalities, a shutdown of activities in large cities like Montreal and Ottawa, and an unprecedented effort in reconstruction of the power grid. The ice storm led to the largest deployment of Canadian military personnel since the Korean War, with over 16,000 Canadian Forces personnel deployed, 12,000 in Quebec and 4,000 in Ontario at the height of the crisis.
Freezing rain is common in the eastern half of Canada and New England, generally occurring at the narrow boundary between cold air from the east and north and moist air from the south. Typically, a warm air mass will travel northward along the Mississippi Valley and overrun a shallow layer of cold air trapped at the surface. Such a favorable cold air damming happens with an east to northeasterly flow in the St. Lawrence (the predominant wind direction in the St. Lawrence Valley is usually either northeast or southwest) and the Ottawa Valley and along the axis of the Appalachian Mountains.
Snow is produced at upper levels in such a winter storm system, but it eventually melts into rain as it falls through a warm air layer of above-freezing temperature (of at least 1,200 feet (370 m) in-depth) associated with the overrunning. The rain passes through colder air near the surface and is supercooled. When that rain touches the ground or any other cold surface in the cold air below, the droplets freeze on contact, creating accumulations of ice. If the cold air layer is too thick, the droplets refreeze before hitting the ground and form ice pellets, which are usually less hazardous.
The Montreal area typically receives freezing rain between 12 and 17 times a year, averaging between 45 and 65 total hours of rain. However, a freezing rain storm usually lasts only a few hours and leaves a few millimeters (fractions of an inch) of accumulation. It renders roads and sidewalks slippery, causing minor traffic collisions, but road crews use de-icing material to take care of it. Power lines and other equipment are built according to tough standards, since large accumulation events have happened many times prior to 1998. In Quebec, standards were reinforced after a storm left 30 millimetres (1.2 in) to 40 millimetres (1.6 in) of ice in Montreal in 1961.
Prior to the 1998 storm, the last major ice storm to hit Montreal (1961) deposited around 30 to 60 millimetres (1.2 to 2.4 in) of ice. However, the 1998 storm left deposits twice as thick, downing power lines all over the region, damaging most of the trees in Montreal, and leaving streets covered in a thick, impassable layer of ice.
On January 4, 1998, an upper level low system stalled over the Great Lakes, pumping warm and moist air from the Gulf of Mexico toward the upper St. Lawrence Valley. The upper flow then turned eastward, bringing this air mass down toward the Bay of Fundy. At the same time, a high pressure center was sitting farther north in Labrador, keeping an easterly flow of very cold air near the surface. An unusually strong Bermuda high pressure area was anchored over the Atlantic Ocean, which prevented these systems from moving further to the east, as most winter storms do when they pass over the Great Lakes–St. Lawrence region.
A series of surface low pressure systems passed in this atmospheric circulation between January 5 and January 10, 1998. For more than 80 hours, steady freezing rain and drizzle fell over an area of several thousand square miles of Eastern Ontario, including Ottawa, Brockville, and Kingston, an extensive area in southern Quebec, northern New York, and northern New England (including parts of Vermont, New Hampshire and Maine).
Farther to the south, southern Ontario and western New York, as well as much of the Appalachian region from Tennessee northward, received heavy rain and severe flooding, while further east, the Canadian Maritimes mostly received heavy snow. Exacerbating the problem was a steep drop in temperature that immediately followed the passage of the freezing rain, which combined with the extreme power outages led to numerous indirect deaths due to carbon monoxide poisoning from generators and other sources as people desperately tried to remain warm.
Hub AI
January 1998 North American ice storm AI simulator
(@January 1998 North American ice storm_simulator)
January 1998 North American ice storm
The North American Ice Storm of 1998 (also known as the Great Ice Storm of 1998 or the January Ice Storm) was a massive combination of five smaller successive ice storms in January 1998 that struck a relatively narrow swath of land from eastern Ontario to southern Quebec, New Brunswick and Nova Scotia in Canada, and bordering areas from northern New York to central Maine in the United States. It caused massive damage to trees and electrical infrastructure throughout the area, leading to widespread long-term power outages. Millions were left in the dark for periods varying from days to several weeks, and in some instances, months. It led to 34 fatalities, a shutdown of activities in large cities like Montreal and Ottawa, and an unprecedented effort in reconstruction of the power grid. The ice storm led to the largest deployment of Canadian military personnel since the Korean War, with over 16,000 Canadian Forces personnel deployed, 12,000 in Quebec and 4,000 in Ontario at the height of the crisis.
Freezing rain is common in the eastern half of Canada and New England, generally occurring at the narrow boundary between cold air from the east and north and moist air from the south. Typically, a warm air mass will travel northward along the Mississippi Valley and overrun a shallow layer of cold air trapped at the surface. Such a favorable cold air damming happens with an east to northeasterly flow in the St. Lawrence (the predominant wind direction in the St. Lawrence Valley is usually either northeast or southwest) and the Ottawa Valley and along the axis of the Appalachian Mountains.
Snow is produced at upper levels in such a winter storm system, but it eventually melts into rain as it falls through a warm air layer of above-freezing temperature (of at least 1,200 feet (370 m) in-depth) associated with the overrunning. The rain passes through colder air near the surface and is supercooled. When that rain touches the ground or any other cold surface in the cold air below, the droplets freeze on contact, creating accumulations of ice. If the cold air layer is too thick, the droplets refreeze before hitting the ground and form ice pellets, which are usually less hazardous.
The Montreal area typically receives freezing rain between 12 and 17 times a year, averaging between 45 and 65 total hours of rain. However, a freezing rain storm usually lasts only a few hours and leaves a few millimeters (fractions of an inch) of accumulation. It renders roads and sidewalks slippery, causing minor traffic collisions, but road crews use de-icing material to take care of it. Power lines and other equipment are built according to tough standards, since large accumulation events have happened many times prior to 1998. In Quebec, standards were reinforced after a storm left 30 millimetres (1.2 in) to 40 millimetres (1.6 in) of ice in Montreal in 1961.
Prior to the 1998 storm, the last major ice storm to hit Montreal (1961) deposited around 30 to 60 millimetres (1.2 to 2.4 in) of ice. However, the 1998 storm left deposits twice as thick, downing power lines all over the region, damaging most of the trees in Montreal, and leaving streets covered in a thick, impassable layer of ice.
On January 4, 1998, an upper level low system stalled over the Great Lakes, pumping warm and moist air from the Gulf of Mexico toward the upper St. Lawrence Valley. The upper flow then turned eastward, bringing this air mass down toward the Bay of Fundy. At the same time, a high pressure center was sitting farther north in Labrador, keeping an easterly flow of very cold air near the surface. An unusually strong Bermuda high pressure area was anchored over the Atlantic Ocean, which prevented these systems from moving further to the east, as most winter storms do when they pass over the Great Lakes–St. Lawrence region.
A series of surface low pressure systems passed in this atmospheric circulation between January 5 and January 10, 1998. For more than 80 hours, steady freezing rain and drizzle fell over an area of several thousand square miles of Eastern Ontario, including Ottawa, Brockville, and Kingston, an extensive area in southern Quebec, northern New York, and northern New England (including parts of Vermont, New Hampshire and Maine).
Farther to the south, southern Ontario and western New York, as well as much of the Appalachian region from Tennessee northward, received heavy rain and severe flooding, while further east, the Canadian Maritimes mostly received heavy snow. Exacerbating the problem was a steep drop in temperature that immediately followed the passage of the freezing rain, which combined with the extreme power outages led to numerous indirect deaths due to carbon monoxide poisoning from generators and other sources as people desperately tried to remain warm.