Homegrown development explained

AccuWeather's Bernie Rayno breaks down what homegrown development is.

Transcript

00:00All right, in today's weather, why we're going to do a little double duty for you.

00:08We're going to talk about homegrown development.

00:10That's a uniquely AccuWeather term.

00:12And what in the world is a gyre?

00:14Well, both those homegrown development and gyres are important to the tropical development

00:20we're going to see in the next week.

00:22And again, that highlights our weather wise today.

00:25Let's talk about homegrown development.

00:27Now, homegrown development during the hurricane season, you usually see that when?

00:30In June, early July, and in October.

00:34It occurs when you get a dip in the jet stream coming on southbound here, and that dip in

00:39the jet stream usually brings frontal boundaries and also upper lows that kickstart showers

00:45and thunderstorms over the warm waters of either the Gulf of Mexico, the southwest Atlantic,

00:50and also in the northwest Caribbean, and that starts tropical development.

00:55What they also do is produce what we call a gyre, the Central American gyre, an area

01:00of low pressure in the southwest Atlantic.

01:02How does that happen?

01:03Well, when you get a dip in the jet stream across the Caribbean and the Gulf of Mexico,

01:08you change the wind flow in Mexico and Central America, which usually comes in out of the

01:13southeast.

01:14Now, you're going to bring it out of the west northwest.

01:17At the same time, you still have an easterly flow across the central and eastern Caribbean.

01:22Well, what that ends up doing is producing what we say a counterclockwise flow or a cyclonic

01:27flow and an area of low pressure.

01:29That low pressure starts to produce showers and thunderstorms.

01:32You get a little area of low pressure that breaks off that gyre, comes northward into

01:37the northwest Caribbean, and that's how you can get development from a gyre.

01:42And guess what?

01:43That's exactly what we're looking at here with a high threat of development in the northwest

01:48Caribbean next week.

01:51News and homegrown development, now you know.