What are the key ingredients of creating a winter storm?
By Ken Kostura
There are many ways for winter storms to form. However, all storms have three key ingredients: cold air, moisture and lift. The temperature must be below freezing in the cloud and near the ground for snow and ice to form. Water evaporating from the Atlantic Ocean or a large lake is an excellent source of moisture. Lift causes moisture to rise and form clouds and precipitation. A winter storm can be created many ways, for example by a warm or cold front, lake effect, mountain effect, and upper air disturbance or cyclone moving across the region.
One the more memorable snowstorms occurred on January 28, 1998 when 20.4 inches of snow fell in Blacksburg, Virginia. This storm had a common scenario for heavy snow
over the southern Appalachians with a developing low pressure system across the northeast Gulf of Mexico, and Canadian high pressure situated just north of the area across New England. The low center tracked northward from northern Florida to southeast Virginia by Wednesday morning on the 28 th . Refer to image below for this classical storm track.
Another common mechanism to create large amounts of snow is Lake Effect. Cold arctic air moves across a warm and moist lake resulting in big accumulations. An example of this occurred on the 5th and 6th of March 2001 were 12 to 18 inches of snow fell over the higher elevations of Greenbrier, Mercer and Summers counties of West Virginia.
On January 11-12, 1997 in the town of Montague, downwind of Lake Ontario in western New York, a spotter reported 77 inches of lake effect snow.
Has anyone seen my truck ? coutesy of the NWS in Buffalo, NY
Many times during the winter, mountain effects play a major role when strong cold advection combines with an upslope flow to result in heavy snow. One of the heavier snowfall upslope events occurred on December 29-30, 1997. Over two feet of snow fell in the portions of the Greenbrier Valley of West Virginia.
When all the pieces come together just right, the region has a winter storm!
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