HORRY COUNTY, SC (WMBF) – Hurricane season will officially be here in a matter of hours, and it is important to know the terms commonly used with hurricanes and what they mean. We've heard them all- tropical depression, tropical storm, hurricane, watches, warnings- but what do they all really mean?
A tropical depression forms when a low pressure area is accompanied by thunderstorms that produce a circular wind flow with maximum sustained winds below 39 miles per hour. A tropical depression will be upgraded to a tropical storm when sustained wind gust consistently at or above 39 miles per hour, but less than 74 miles per hour. When a tropical depression becomes a tropical storm, it will then be given a name.
A tropical storm will be upgraded to hurricane status when sustained winds increase to a minimum of 74 miles per hour. Hurricanes will be given a rating of one to five on the Saffir-Simpson Scale, based on sustained wind speed. A Category 1 hurricane will have winds between 74 and 95 miles per hour; a Category 2 will have winds between 96 and 110 miles per hour; a Category 3 has winds of 111 to 130 miles per hour; a Category 4 has winds of 131-155 miles per hour, and a Category 5 has winds of 156 miles per hour or greater. Hurricane winds can be deadly, but the greatest threat is actually from water- whether it is from excessive rainfall that results in flooding or storm surge.
When a tropical storm or hurricane is threatening land, the National Hurricane Center will issue the appropriate watches and warnings. A Tropical Storm Watch means that tropical storm conditions are possible within the specified area. A Hurricane Watch means that hurricane conditions are possible within the specified area; tropical storm and hurricane watches are generally issued about 48 hours before conditions are expected. During a watch, the National Hurricane Center advises that you prepare your home and review your plan for evacuation in case a warning is issued.
A Tropical Storm Warning will be issued when tropical storm conditions are expected in the specified area; a Hurricane Warning will be issued when hurricane conditions are expected. Warnings are usually issued 36 hours in advance of the anticipated onset of tropical storm or hurricane-force winds. During a warning, you should complete storm preparations immediately and evacuate the threatened area if directed to do so by local officials. In extreme cases, an Extreme Wind Warning will be issued if sustained winds of 115 miles per hour or greater are expected to begin within an hour- if this were to happen, you should immediately seek shelter in the interior portion of a well-built structure.
It is extremely important to know the terms used with hurricanes and tropical storms and to have a set plan in place as to what to do if a hurricane or tropical storm threatens. It could very well save your life.