Preparing for severe weather as winters transitions to spring

By Dave

CHARLESTON, S.C. (WCIV) - Spring is a time of transitionacross the United States. Cold Canadian air wants to keep its hold with chillytemperatures, but warm moist air is ready to arrive out of the tropics andbring back summer conditions.{}

As these two air masses collide, violent thunderstorms canoften be the result.

March through May is climatologically the most active timefor spring severe thunderstorms in South Carolina. Fortunately, the occurrence of theseoutbreaks is less frequent than in surrounding states.

Take for instance the April 14-16, 2011 North Carolina tornadooutbreak that killed 43 people along with straight line winds, and the April25-28 2011 Deep South tornado outbreak which killed just under 350 people. Althoughviolent thunderstorms are less common in the Lowcountry, they do occasionallystrike and cause loss of life and property. The main threats for severe weathercome from straight line winds, hail, tornadoes and even flooding.

The best way to be prepared for these phenomena is to knowwhen there is an elevated risk.

This weather typically occurs in the proximity of a severethunderstorm. According to the National Weather Service, that is any stormwhich produces a tornado, has straight line winds of at least 58mph, and could containhail one inch in diameter or greater.

A Severe Thunderstorm Watch is issued by the Storm Prediction Center when atmosphericconditions are favorable for severe thunderstorms. If certain weatherconditions may be present for thunderstorms to be particularly severe andpossibly produce tornadoes, then a Tornado Watch will be issued. Watchesusually last for four to eight hours and are typically put in place at leastand hour ahead of any severe or tornadic thunderstorms.

A Severe Thunderstorm or Tornado Warning is more dangerousbecause damaging weather is either occurring or has been detected to be ongoingby Doppler radar. This is when people need to seek safe shelter immediatelyuntil the violent thunderstorm has passed.

Warnings are issued by the local National Weather Serviceoffice and are usually in place for 30 minutes to one hour depending on thesize and the speed of the thunderstorm.

If there is any damage once the storm passes, report it tolaw enforcement, the National Weather Service, or ABC News4 to help keep yourneighbors in the Lowcountry out of harm's way.

Stay safe during the upcoming spring severe weather season,and know that you will get the latest watches and warning on ABC News4 on air,online and on the go.