GREENVILLE, N.C. — It’s officially hurricane season, and with that, let’s dive into the details of hurricane formation.
There are a few key ingredients that must come together just perfectly in order to form a tropical system.
It all starts with the warm ocean waters. During the day, the heat from the sun evaporates warm moist air just above the ocean surface. This warm moist air rises, condenses, and cools into ice crystals which make up a cloud. This ongoing vertical motion, otherwise known as convection, eventually leads to thunderstorm development.
This thunderstorm activity will continue to strengthen as long as there is a large amount of moisture present in the mid-levels of the atmosphere. There also cannot be a whole lot going on in terms of wind shear. Wind shear is when winds are moving in several different directions, which has the capability of tearing apart a tropical system. The final key ingredient includes warm ocean waters at 80 degrees F or higher. With high temperatures comes more energy needed to fuel the storm.
Once these three ingredients work together, the disturbance will eventually begin to rotate naturally because of earth’s rotation. With organized cloud cover and thunderstorms, a tropical depression has formed with winds 38 mph or less. If strengthening continues, a tropical storm will form with organized strong thunderstorms and circulation with winds ranging from 39 to 73 MPH. A hurricane has officially formed once the winds contained within the center of circulation reach winds of 74 mph or more with severe tropical thunderstorms.
Most hurricane’s that form in the ocean don’t actually ever make landfall. This is because those key ingredients must all work together with a traveling tropical cyclone in order to get it to land.