Storm of the Century
From March 12 to 14, 1993, North America's eastern seaboard was bludgeoned by a blizzard, powered by a cyclonic storm, that left most regions covered in an average of 15 inch of snow and caused about 10 million power outages. It affected 40% of the US population, causing 318 deaths, and leaving property damage worth 8.7 billion dollars in its wake.
Denizens of North America and Canada are no strangers to the freezing fury of snowstorms, a recurrent phenomenon that brings life to a standstill, every winter. Arising from the interplay of moisture, temperature, and pressure differences, snowstorms are some of the most potent destructive forces of nature. Classified as winter storms, they are known as 'Blizzards' in their more severe incarnation.
Capable of widespread disruption, snowstorms can literally bring life in any region to a standstill, due to the compromised visibility conditions, thick snow cover, and probable after-effects which include avalanches, coastal flooding, and extreme cold.
How are Snowstorms Formed?
To make the perfect snowstorm, the essential ingredients are cold air, moisture, and lift. Low temperatures set the stage for snow precipitation to occur, moisture from evaporating water bodies feeds the air currents, and lift facilitates the creation of clouds at higher altitudes that ultimately causes snowfall.
The formation of such a storm begins when a high pressure system (an envelope of air over a very low temperature land mass), called a ridge, comes in contact with a substantially low pressure system (an envelope of air over a warmer land mass). Air from heavy pressure areas always moves towards low pressure areas to equalize pressure. In this case, the high pressure cold winds start blowing towards the low pressure areas.
The low pressure air contains high moisture content. Clouds are formed as the hot humid air moves up, replaced by cold air below. Then finally when precipitation occurs, the water droplets coming down freeze due to low temperatures and what we get is a snowstorm. Here are the four weather conditions (warm front, cold front, lake effect, and mountain effect) that typically lead to a snowstorm:
If the temperature falls very much below freezing point, an ice storm occurs. Snowstorms mostly occur in winter but are also known to occur in early spring, as well as late autumn. Sometimes, they also occur in exceptionally cold summers. The most powerful snowstorms occur in March.
Types of Snowstorms
Depending on the intensity of snow fall, formation pattern, degree of reduction in visibility, and wind speeds, snowstorms can be classified into various types:
High intensity snowfall in short and sudden bursts, accompanied with gusts of wind, resulting in significant accumulation, is known as a snow squall. They are also known as whiteouts, due to the sudden reduction in visibility that characterizes their arrival. They can be particularly hazardous for motorists and are the cause of numerous accidents. Squalls are a common phenomenon in the Great Lakes region of North America. The two most distinct forms of snow squalls are - lake effect (described above) and frontal (similar to cold front illustrated before).
When accumulated snow is blown by the wind to altitudes as high as 6 feet or more, significantly reducing visibility to less than 7 miles, the weather condition is known as blowing snow. The blown snow may be swept off the surface or falling snow. Blowing snow indicates a blizzard in the making. When the blown snow stays below 6 feet, it is known as drifting snow.
In particular, snowstorms with wind speeds greater than 35 mph (30 knots) and thick snowfall that reduces visibility down to less than quarter of a mile (400 m), for at least three hours, are officially termed as blizzards. Temperatures may dip to less than -12°C (10°F ) or lower. The most destructive blizzards are characterized by wind speeds in excess of 72 km/h (45 mph). Ground blizzards are created by snow being swept off the ground by strong winds.
Every year, from September to April, the eastern coast of United States is hit by a massive cyclonic storm powered by the confluence of the warm air from the gulf stream, meeting the cold air from the Arctic. It is known as a Nor'easter, owing to the north easterly winds that direct it inland. These storms cause blizzard-like conditions, coastal flooding and drive hurricane-force winds.
Top 10 Biggest Blizzards of All Time
Weather, by its very nature, is unpredictable. Severe weather conditions like blizzards have always inflicted massive devastation, almost every year, in some area of the globe. But once in a while, a particularly mean blizzard will turn up that redefines the very idea of devastation. There is no objective way of classification that can precisely identify and rank the ten most destructive blizzards of all time. The following ranking has been generated on the basis of the severity of the blizzard, measured in terms of snow cover, wind speeds, and scale of inflicted damages. Besides the 'Storm of the Century', described at the start, here are some of the most devastating snowstorms ever recorded.
#10: Chicago Blizzard of 1967
On January 26, 1967, Chicago was hit by a blizzard that left the city covered in a record-breaking 23 inches of snow. Wind speeds of 53 mph were recorded, with snowdrifts up to 10 feet observed. 76 people lost their lives because of the storm that brought the entire city and surrounding regions to a standstill.
#9: Eastern Canadian Blizzard of March, 1971
From March 3 to March 5, 1971, a nor'easter storm struck eastern Canada, causing at least 30 deaths across the province and inflicting damages to the tune of a million dollars. The city of Montreal saw a total of 18.5 inches of snow, while Quebec received 31.5 inches. It was one of the worst winters to have hit eastern Canada.
#8: North American Blizzard of 2006
This was another nor'easter that struck Northeastern United States, between February 11 and February 13, 2006. With a maximum snow accumulation reading of 30.2 inches, the storm affected Virginia, Maryland, District of Columbia, Pennsylvania, New York, New Jersey, Delaware, New England, and Atlantic Canada. New York city recorded 26.9 inches of snow, while all the rest of the major cities within the belt received about a foot of snow. The storm inflicted USD 5 million in damages, causing 3 recorded deaths.
#7: Northeastern United States Blizzard of 1978
One of the most destructive and crippling blizzards to have struck Northeastern United States, between February 5 to February 7, 1978, it affected the New York metropolitan area, New Jersey, and New England. By the time it had dissipated, it had caused 100 deaths and left close to 4500 injured, besides recording total damages to the tune of USD 1.83 billion (2010 dollars). All the major cities measured record-breaking snow accumulation, with Boston receiving 27.1 inches, Atlantic City receiving 20.1 inches, and Providence recording 27.6 inches of snow.
#6: Lhunze County, Tibet (2008)
Tibet was struck by its worst snowstorm in 2008, with nearly 5 feet of snow blanketing most of Lhunze county. In 36 hours, it killed 7 people, caused more than 144,000 cattle deaths and left hundreds trapped in snow. It took almost three days to clear off the snow cover, for life to return to normalcy.
#4: The Great Blizzard of 1899
Known for the record low temperatures (up to -61°F), this blizzard, riding on a cold wave, descended upon Southern USA, particularly Washington DC, New Orleans, and Florida. The storm was further powered by ocean-effect snow (a phenomenon similar to lake effect) making the mercury dip below zero level. Cape May, New Jersey, was the worst affected, with 34 inches of snow piling up.
#3: Mount Shasta Storm (1959)
Only overshadowed by the storm of the century that struck in 1993, the Mount Shasta Ski Bowl snowstorm delivered 189 inches of snow in 1959, driving itself into record books. Since it mostly struck the mountainous regions, no loss of life and property was reported. It still holds the record for the most amount of snow deposited in a single snowstorm.
#2: The Great Snow of 1717
Even three centuries later, the blizzard of 1717 that struck New England and New York colonies hasn't been forgotten. A series of Nor'easters struck the region in the first week of March, leaving both the colonies covered in five or more feet of snow. According to the earliest records, Boston was the most affected city with snowdrifts reaching 25 feet.
#1: The Buffalo Blizzard (1977)
With the snowfall topping at 199.4 inches and winds blowing at 45 mph to 69 mph, the Buffalo Blizzard of 1977, tops the list. Snowdrifts up to 25 feet were recorded, rendering visibility down to zero, making air and road travel impossible. The lake effect snow, generated by lake Ontario, combined with formidable snow cover, built previously, led to the deadliest of blizzards to have ever struck the upstate New York area.
Some 'Chilling' Facts
New York state has the snowiest cities in the United States of America. It's the most frequently snowstorm-struck state.
The most severely snowstorm-affected city in the United States is Valdez in Alaska, which receives an annual snowfall, amounting to 260 inches.
All over the United States, the average daily snowfall, caused by these storms is 2 inches. For mountainous areas, it is almost 7 inches.
Snowstorms lead to rapid accumulation of snow, resulting into avalanches, which is tons of snow, traveling at speeds reaching 200 miles per hour. In fact, 80% of winter avalanches are triggered by snowstorms.
Frostbite, hypothermia, and wind chill are some of the most common health hazards caused by snowstorms.
The Rockies are most affected by mountain-effect triggered snowstorms and avalanches. The mid-west, owing its proximity to the Great Lakes is is pounded by heavy snow and blizzards caused by the lake-effect.
Snowstorms and especially blizzards can be dangerous atmospheric calamities of unpredictable nature. Advanced warning systems have been put in place which can help people in preparing for the onslaught of these natural disasters. The National Weather Service ( NOAA) is the best source of information for alerts regarding winter storms and other disruptive atmospheric phenomena.