Winter is around the corner. Time to get prepared.
The following web story is a direct transcription from the National Weather Service regarding winter weather awareness week. We are an important partner with the National Weather Service to educate and remind everyone about the many hazards that a New York winter brings and how to keep safe for the winter season. This is the second of a five part series on winter weather safety. Today’s topic will focus on the types of heavy snow events which impact central New York.
Heavy snow can immobilize a region and paralyze a city. This leads to stranding commuters, closing airports, stopping the flow of supplies, and disrupting emergency and medical services. If enough heavy snow occurs from snowstorms, then roofs may sustain damage. Occasionally, roofs may collapse and knock down trees and power lines. Homes and farms may be isolated for days and unprotected livestock may be lost. The cost of snow removal, repairing damages, and the loss of business can have severe economic impacts on cities and towns. Heavy snow in central New York is defined as 7 inches or more falling in a 12 hour period or 9 inches or more falling in a 24 hour period. Warnings are issued when these amounts are in the forecast. Advisories are issued for lesser amounts, generally 4 inches or more in a 12 hour period. Heavy snow can be produced by nor’easters, overrunning situations and localized lake effect snow bands. Smaller amounts of snow are often produced by Alberta clippers.
Nor’easters are intense areas of low pressure that typically develop along the eastern seaboard most often during late fall, winter and early spring. They usually bring strong northeast winds to areas near the coast as they move north along it. Some memorable nor’easters in recent years included the President’s day snowstorm of 2003, the February 11th and 12th storm of 2006 and the Valentine’s Day snowstorm of 2007. Snowfall rates in nor’easters can reach 2 to 4 inches per hour and these rates can last for several hours. This type of snow also has a high water content, making it weigh more than other types of snow. Roofs are most susceptible to extreme amounts of high water content snow.
Overrunning can also produce steady snow. This occurs when warm air aloft flows over cold air near the surface. Overrunning occurs most often when a large dome of high pressure is located in southeastern Canada and a warm front is approaching our region from the south or southwest.
Lake effect snows often occur in the late autumn and winter downwind of the Great Lakes when cold arctic air sweeps across the relatively warmer waters of the lakes. Snow squalls will typically form along the lee shores of the lakes and move downwind. These squalls can result in locally heavy snows with reduced visibilities in fairly narrow bands. Most lake effect snowfall occurs in the strong cold air flow after the passage of a cold front. The lake effect snow which impacts central New York usually originates downwind of Lake Ontario, but sometimes there will be bands from Lake Erie which can impact the southern tier and Finger Lakes region of New York. When Lake Ontario snow bands receive moisture from Lake Huron, Lake Superior, or Georgian Bay, snowfall rates become even stronger. The areas of central New York which receive the most lake effect snow are the Tug Hill Plateau, western Mohawk valley and the greater Syracuse area including the Finger Lakes. Occasionally, area south-southeast of the Finger Lakes can receive locally enhanced snow, as well.
An Alberta clipper is an area of low pressure that usually forms over the province of Alberta in Canada, east of the Rocky Mountains. Alberta clippers usually move very quickly southeast from their point of origin and usually bring only light snow as they cross our region unless they intensify off the east coast. They also allow colder air from Canada to move into our region in their wake.
Some snow terms which are commonly used include blizzard, blowing snow, snow squalls, snow showers and snow flurries. A blizzard is a winter storm which has sustained winds or frequent gusts of 35 mph or more, with considerable falling and or blowing snow frequently reducing the visibility to at or below one quarter mile, and these conditions last for 3 hours or more. Some of the greatest snowfalls on record in central NY occurred during blizzards. Thirty to 45 inches fell over a large part of central NY during the blizzard of 1993, and between 2 and 3 feet fell during the blizzard of 1966. Blowing snow is wind driven snow that reduces visibility. Blowing snow may be falling snow or snow already on the ground that is picked up by the wind. Snow squalls are brief intense snow showers accompanied by strong gusty winds which may produce significant snow accumulations. Snow showers have snow falling at varying intensities for brief periods of time with some snow accumulation possible. Snow flurries are light snow which falls with little or no snow accumulation. For additional information on winter weather safety, click here.
For more on your weather forecast, click on “Weather” and then the “Live Triple Doppler Radar” tab on our weather page. Make sure you refresh the Doppler radar to see the very latest information, as well. Furthermore, we have our new Interactive Doppler Radar on our website. You can zoom down to street level with Interactive Doppler Radar. You are in total control of where the radar can zoom in. Give it a try. Plus, click on our Severe Weather Tab and our Watches and Warnings map to see the very latest county specific watches and warnings. In addition, you can “follow” along with me on Twitter by either clicking on the “follow” button on the Twitter section of our weather page or by visiting www.twitter.com/PeteWeatherBeat.
