When you see meteorologists discussing the forecast for an impending hurricane, there are a few key terms you're likely to hear. AccuWeather's Anna Azallion breaks them down here.
00:00Well, when we're talking about the tropics and we show you satellite images like this, well, with Gabrielle, alright, it's clear what you're looking at, but a lot of the times we talk about the other things I have circled, tropical waves, and if you've been sitting there thinking, okay, what the heck is a tropical wave? Well, you're not alone, so let's dive into it.
00:18So, at its core, a tropical wave is really just an area of low pressure in the atmosphere, and the key here is that they move westward off the coast of Africa into the Atlantic. The majority of our tropical storms, tropical depression, hurricanes, they start as a tropical wave, so that's why a lot of times we're telling you we're tracking this tropical wave because it could strengthen into something else.
00:41Now, there's a couple ingredients, so to speak, that you need in order for a tropical wave to develop into a tropical depression, storm, or a hurricane.
00:50Now, this time of year, the warm water, that is usually not a problem, but a lot of times we're talking about wind shear. That's been a big issue with Gabrielle over the last couple of days, as well as dry air.
01:01So, let's talk about wind shear specifically because that's another thing you might be sitting there kind of scratching your head thinking, okay, what exactly is this? Why is it such a problem?
01:11There's two types of wind shear. We're going to talk about vertical wind shear, but it's basically changing wind direction or speed over vertical or horizontal distance. Again, we're talking about vertical wind shear because that's what's relevant with a tropical storm or a hurricane.
01:24So, think of kind of layers of a cake or stacked pancakes as our tropical storm in this instance. So, a tropical storm, it wants weak wind shear in order to continue going on and even to strengthen into a hurricane.
01:38But what happens when we have stronger wind shear is our storm gets a little lopsided. Now, if it's a strong hurricane, it can kind of overcome this and even sometimes a tropical storm, but a lot of times it means it weakens.
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