Tracking the tropics

Tropical trouble ahead? AccuWeather's Bernie Rayno explains what's brewing off the Southeast coast.

Transcript

00:00When you take a look at the tropics this time of the year, you always have to worry about what we call homegrown development.

00:06This is a unique AccuWeather term that we coined many years ago.

00:10What is it? It's tropical development occurring close to the United States.

00:14Now, this includes the Southwest Atlantic, the Gulf, and also into the Northwest Caribbean.

00:20How it happens? Dip in the jet stream coming southbound that interacts with those warm waters.

00:26Now, what this dip in the jet stream can do, it can do a couple of things.

00:30It brings in a frontal boundary that can stall.

00:33You get showers and thunderstorms to develop, and in time, those thunderstorms can develop into a tropical system.

00:39Or it can bring an upper low.

00:41Same process. It has to sit over those waters for a period of time.

00:45Or it can produce a gyre in central parts of America.

00:50All right? So those are the three ways we get it.

00:52All right. Are we seeing that right now, an interaction between the jet stream and the tropics?

00:57Yeah. You have this upper low. There it is.

00:58As you can see, it's spinning north and west of Tampa.

01:03Now, in order for this to develop, this would have to sit here for a minimum of 48 hours.

01:09However, that ain't happening.

01:12That's going to lift northward.

01:13In fact, this upper low is going to go right across southern Georgia later tonight and into tomorrow.

01:18And then it moves back out to sea, but it's going to be leaving the Carolina coast later tomorrow.

01:23So when you look at the ingredients for homegrown development, you do have the interaction between the jet stream and tropics with this.

01:30The upper low front is over warm water, but it doesn't sit over a minimum of 48 hours.

01:35I think the chance of any development here later this week is close to zero.

01:41I'm no longer concerned about it.

01:43All right.

01:43The other area to watch.

01:44Let's keep an eye out on Central America.

01:47There could be some development here next week.