WeatherTalk: Hurricanes begin as a complex of thunderstorms
When tropical storms become better organized, the system intensifies.
FARGO — Tropical depressions, tropical storms and hurricanes all get their start as a complex of thunderstorms originating in the tropics, sometimes as far away as the coast of Africa). These "tropical waves" are often the precursor to further development. A tropical depression is a tropical wave that develops a center of low pressure, poorly organized and with winds of less than 40 mph. When the tropical depression intensifies beyond a sustained 39 mph wind, it is named a "tropical storm" and given a name — which will be discussed in tomorrow's piece.
When tropical storms become better organized, the system intensifies. Once the sustained winds reach 74 mph, the storm is upgraded to a hurricane. There are five categories of hurricane, with category 3, 4 and 5 being considered a "major hurricane." Category 5 hurricanes need winds of at least 157 mph, and some, like Hurricane Patricia in 2015, can reach sustained winds upwards of 215 mph.