Carville, LA

..severe weather awareness week in Louisiana and Mississippi...
   ... February 13 through February 17 2012...

The week of February 13 through February 17 has been proclaimed as
severe weather awareness week in Louisiana and Mississippi.
Late winter and Spring months typically bring the highest frequency
of severe weather to Gulf Coast region. Severe weather awareness
week is good time to review severe weather safety plans and ensure
you have a means to receive timely warnings.

... Severe thunderstorm hazards and safety information...

By definition... a thunderstorm is classified as severe if it produces
hail 1 inch in diameter or larger and/or wind gusts 58 mph or
stronger.

Downward rushing currents of air called downdrafts often
occur along the leading edge of thunderstorms. Very strong
downdrafts are often called downbursts. Wind gusts in severe
thunderstorms can reach 60 mph... and can sometimes approach 100
mph. The strong thunderstorm wind gusts can produce a roaring
sound... often mistaken for a tornado. These strong wind gusts
associated with severe thunderstorms can damage or destroy
Mobile homes... .down trees and power lines... and damage poorly
constructed buildings.

Large hail can also occur in severe thunderstorms. Hailstones are
precipitation in the form of lumps of ice that form during some
thunderstorms. Hailstones are usually round and range from pea size
to the size of a grapefruit. Hail is most devastating to crops but
can also cause heavy damage to automobiles... roofs... and aircraft.

While large hail is uncommon in south Louisiana or extreme south
Mississippi... .it can occasionally occur.

On may 14... 2008 large fell in wide swath from southern Pointe
Coupee Parish across Baton Rouge into Livingston Parish.
Considerable damage occurred to house roofs and automobiles from
both of these events. On March 29 of last year..the combination of
wind... and wind driven hail caused considerable property damage on
the West Bank areas of New Orleans

Hailstones generally form in thunderstorms between the currents
of rising air... the updraft... and the current of air descending
toward the ground... the downdraft. Large hailstones indicate
strong updrafts in storms. The larger the hail the stronger the
updraft needed to hold it aloft in the thunderstorm. It is for this
reason that in storms that produce tornadoes... the hail often falls
directly to the northeast or east of the path of a tornado. The
strong updraft is associated with the part of the storm that can
produce a tornado.

If a severe thunderstorm approaches with the threat of damaging
winds and large... seek shelter in an interior on the lowest floor
of a well constructed building away from doors or windows. An
interior small room such as a bathroom or closet..or even a hallway
away from doors and windows is the best location

Throughout severe weather awareness week... the National Weather
Service will issue public information statements on severe weather
safety.