When does a tropical depression become a tropical storm? And when does a tropical storm become a hurricane? What's the ...

Those categories are based on the Saffir-Simpson Hurricane Wind Scale ... % of deaths from tropical cyclones in the U.S. have historically been caused by rainfall flooding, storm surge, rip ...

Tropical systems are categorized by wind speed, but experts say there's much more to the story when it comes to storm impacts ...

When it reaches 39 mph sustained winds, it is labeled a tropical storm. It isn’t until ... At that point, the NHC uses the Saffir-Simpson Hurricane Scale of intensity to categorize it on a ...

When it reaches 39 mph sustained winds, it is labeled a tropical storm. It isn’t until sustained winds of 74 mph or greater are reached that a system will be named a hurricane. At that point, the NHC ...

A tropical storm is a tropical cyclone that has maximum sustained winds of between 39 and 73 mph – a step above a tropical depression.

"The Saffir-Simpson scale is a measure of wind speed ... At the time it was in North Carolina, it was a tropical storm. To folks in the mountains, however, it was life-altering." ...

When it reaches 39 mph sustained winds, it is labeled a tropical storm.