Public Information Statement
Issued by NWS Columbia, SC

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NOUS42 KCAE DDHHMM PNSCAE SCZ015-016-018-020-021-022-025-026-027-028-
029-030-031-035-036-037-038-041-GAZ040-063-064-065-077-091200-

PUBLIC INFORMATION STATEMENT
NATIONAL WEATHER SERVICE COLUMBIA SC
630 AM EST Thu Dec 8 2016

...Winter Weather Awareness Week Continues...

Freezing rain is one of the more common winter weather phenomena we
experience in the Midlands and Central Savannah River Area. It is
actually more treacherous and life threatening than snow. Why?
Because freezing rain adds more weight to objects it falls on and
often causes trees and power lines to come down. A major event could
leave people without power and heat for a considerable period of
time.

Freezing rain occurs when there is a layer of warm air above
colder air at the surface. When the temperature at the surface is at
or below 32 degrees Fahrenheit and the depth of the cold air is
shallow, rain falling into it from the warm layer above freezes on
contact. Ice accumulation of even an eight of an inch can cause very
hazardous driving conditions as the ice is difficult to see on the
roadways.

An Ice Storm Warning is issued when a quarter of an inch of ice or
more is expected. A Freezing Rain Advisory is issued when less than
a quarter of an inch of ice is expected.

Sleet develops in a similar situation with warm air above cold air
at the surface. The only difference is that the depth of the cold
air is greater so the rain has more time to freeze into ice pellets
or sleet before it reaches the ground.

Tomorrow we will discuss wind chill, frostbite and hypothermia.

$$



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