Wednesday, January 28, 2009

Texas Ice Storm January 2009

An ice storm is a type of winter storm characterized by freezing rain, also known as a glaze event or in some parts of the United States as a silver thaw. The U.S. National Weather Service defines an ice storm as a storm which results in the accumulation of at least 0.25-inch (0.64 cm) of ice on exposed surfaces. From 1982 to 1994, ice storms were more common than blizzards and averaged 16 per year.
Ice storms occur when a layer of warm air is between two layers of cold air. Frozen precipitation melts while falling into the warm air layer, and then proceeds to refreeze in the cold layer above the ground. If the precipitate is partially melted, it will land on the ground as sleet. However, if the warm layer completely melts the precipitate, becoming rain, the liquid droplets will continue to fall, and pass through a thin layer of cold air just above the surface. This thin layer of air then cools the rain to a temperature below freezing (0 °C). However, the drops themselves do not freeze, a phenomenon called supercooling (or forming "supercooled drops"). When the supercooled drops strike ground below 0 °C or anything else below 0 °C (power lines, tree branches, air craft), they instantly freeze, forming a thin film of ice, hence freezing rain.
While meteorologists can predict when and where an ice storm will occur, some storms still occur with little or no warning. Most ice storms are thought to form primarily in the north-eastern US, but damaging storms have occurred farther south. An ice storm in February 1994 resulted in tremendous ice accumulation as far south as Mississippi, and caused reported damage in nine states. More timber was damaged than that caused by
Hurricane Camille. An ice storm in eastern Washington in November 1996 directly followed heavy snowfall. The combined weight of the snow and 25 millimetres (0.98 in) to 37 millimetres (1.5 in) of ice caused considerable widespread damage. This was considered to be the most severe ice storm in the Spokane area since 1940.
The freezing rain from an ice storm covers everything with heavy, smooth glaze ice. Ice-covered roads become slippery and hazardous, as the ice causes vehicles to skid out of control, which can cause devastating car crashes as well as pile-ups. Pedestrians are severely affected as sidewalks become slippery, causing people to slip and fall, and outside stairs can become an extreme injury hazard.
In addition to hazardous driving or walking conditions, branches or even whole trees may break from the weight of ice. Falling branches can block roads, tear down power and telephone lines, and cause other damage. Even without falling trees and tree branches, the weight of the ice itself can easily snap power lines and also break and bring down power/utility poles; even steel frame
electricity pylons have been sent crashing to the ground by the weight of the ice. This can leave people without power for anywhere from several days to a month. According to most meteorologists, just one quarter of an inch of ice accumulation can add about 500 pounds of weight per line span. Damage from ice storms is highly capable of shutting down entire metropolitan areas.

That's an Educated Definition...

Here is Texas We Call 'em Freakin' Frozen Messes!

(Amoung other things!)

Hopefully Anyone experiencing Radical weather will SURVIVE SAFELY!

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