National Weather Service Forecast Office of Cheyenne, WY/ Ben Jacquot
Blizzards
Can you image winds blowing at 75 mph (120 kph), snowfall of 43 inches (1 meter), lost electrical power, and roofs collapsing due to the weight of the snow? These events were part of the Blizzard of 1993 that hit the entire East Coast of the United States.
The National Weather Service defines a blizzard as a storm with large amounts of snow or blowing snow, winds greater than 35 mph (56 kph), and visibility of less than ¼ mile (0.4 km) for at least three hours. Some blizzards have no falling snow. Instead, snow that had fallen before the blizzard is blown around or drifts in a way to create these conditions. This type of blizzard is called a ground blizzard. Conditions for a blizzard usually will build up on the northwestern side of a powerful storm system. The strong winds are from the difference in pressures between two systems. This means the difference in the low pressure system which is causing the stormy weather and the high pressure system to the west of the low.
The word blizzard was first used in the United States during the 1870’s when a snowstorm in Iowa was described as a blizzard. This word has been used throughout the United States and England ever since.
Blizzards are most common in the United States mostly the upper Midwest and the Great Plains according to the National Weather Service. Other countries that have blizzards include Canada and Russia. Russia uses a different name for blizzards, "purgas". Blizzards can occur all over the world. Iran experienced a blizzard in January of 2008 where the temperatures reached -11ºF (-24ºC), and record snowfalls were recorded. Places near the equator can experience blizzards especially at high altitudes.
Conditions of a blizzard can be severe. Travel becomes dangerous when the blowing snow causes whiteout conditions and sky and ground look white. Roads can be partially or fully blocked by drifts of snow that have been caused by the blowing snow. Many times cold temperatures are part of blizzard conditions. The cold temperatures can cause frostbite or hypothermia.
