KNOXVILLE, Tenn. (WVLT) -- When I was visiting with the students in Jellico, they wanted to know more about hurricanes. While you may not think you need to know about tropical storms, there are some major impacts on the amount of rain we get here throughout the summer, plus it’s important to understand if you visit any beaches during this time.
There are various classifications for tropical storms, from depressions to storms and hurricanes.
Tropical formations have stages, sometimes the development is very fast and other times it can drag out over an extended period of time.
Tropical depression is the first stage. But, before that it may be referred to as a tropical system or tropical activity. This means it’s not quite strong enough to be categorized yet.
Tropical Depression - a low pressure area with thunderstorms that produce a circular wind flow with maximum sustained winds below 39 mph. Most tropical depressions have maximum sustained winds between 25 and 35 mph.
In the U.S., the National Hurricane Center (NHC) is responsible for issuing advisories upgrading or downgrading tropical activity. Reconnaissance aircraft missions are sent by the NHC flying into tropical storms to gather data, like wind speeds, to aid in making these classification changes. Surface data from islands, buoys and vessels can also be used to make changes.
Tropical Storm – cyclonic circulation becomes more organized and maximum sustained winds gust consistently at or above 39 mph, and no higher than 73 mph. Tropical storm status is when the naming of the storm takes place.
Hurricane Classification - A tropical storm is then upgraded into Category 1 hurricane status as maximum sustained winds increase to between 74 mph and 95 mph. The Saffir-Simpson Hurricane Scale is used to rate hurricane intensity in the Atlantic Basin, with Category 1 being a less intense storm and Category 5 very intense.
Hurricane season officially runs from June 1st through the end of November, but tropical storms can occur at any time of the year.