Severe Weather Awareness Week: Severe Thunderstorms
POSTED: Tuesday, March 5, 2013 - 6:43am
UPDATED: Monday, March 11, 2013 - 9:07am
STORMTRACKER33 — This week is National Severe Weather Awareness Week for Louisiana. Each day a new topic will be featured to help get you prepared for the upcoming Spring severe weather season. The first topic on the list is Severe Thunderstorms, and the National Weather Service has some tips to keep you ahead of the storm.
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 in our region.
On May 14, 2008, large hail fell in a 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.
A few weeks ago, On the evening of February 24, Large hail, up to the size of golf balls fell across the West Bank areas of the New Orleans area resulting in property damage. 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.