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Winds
By its basic definition, a blizzard may arise with no snow falling at all: What is required is strong, sustained winds that whip up snow on the ground to induce whiteout conditions. A fine, powdery type of snow often is involved, being easily sent airborne. Drifting snow refers to snow particles strung along in drifts, usually within five feet of the ground; blowing snow can entirely veil a person's visibility. Such blizzards, fueled by drifting and blowing snow, are often called "ground blizzards," and are especially common on tracts of open, snowy terrain, such as prairies and steppes.
Frontal Blizzards
Frontal weather systems refer to air masses of distinct properties moving through the lower atmosphere, confronting other bodies of air with different properties. Blizzards certainly can be associated with winter storm fronts, the low-pressure center of the system drawing in strong winds, and the clash of air masses inducing precipitation. Frequently, according to the National Weather Service, blizzard conditions arise on the northwestern edge of a storm system, where the extreme difference in pressure between the center of the disturbance and areas westward results in high winds that can blow falling precipitation horizontally and lift already-fallen snow.
Mountain Blizzards
Blizzard conditions often descend upon mountains, where the rugged topography provokes high winds and snow, especially in winter at high elevations, is often ample. Shear winds of any kind may whip up a blizzard along ridgelines or summit slopes from fallen snow. In the Cascade Range of the Pacific Northwest, winter is defined by relentless storm systems moving inland off the North Pacific and dumping huge quantities of snow in the high country. Such storms, defined by high winds, often result in whiteout periods in the mountains.
Lake-effect Snows
Areas downwind of large bodies of water in snowy country often receive large amounts of snowfall during the winter. This is termed lake-effect snowfall, and if significant winds are present, blizzard-like conditions may arise. In the U.S., lake-effect snowfall is pronounced along southern and eastern shores of the Great Lakes. The lakes heat up and cool down more slowly than the land because of the different molecular structure of water, and their temperatures are in general more moderate. Cold polar air masses sloughing across the lakes are warmed during the passage and thus made unstable; evaporation off the lake surface increases their moisture content. This moisture is shed in the form of heavy snows when the air masses hit land again. Huge amounts of precipitation often result: Over a five-day period in December 2001, Buffalo, N.Y., in the lee of Lake Erie, received close to 7 feet of lake-effect snow.