Hurricanes often get stronger in an extremely short time. How does that happen? We find out, in the latest edition of "Science Behind the Forecast."
Bill Burton: It's time for us to take a look at the Science Behind the Forecast, as I am joined by WAVE 3 meteorologist Tawana Andrew. Good morning, Tawana.
Tawana Andrew: Good morning. We're talking about a concerning part of hurricane season, especially when we're looking back at storms like Hurricane Helene.
BB: Definitely. It seems as if hurricanes are getting bigger and getting bigger faster, and that's what we're talking about today. The idea of rapid intensification of hurricanes. Tell us about that.
TA: So the National Hurricane Center defines rapid intensification as an increase in maximum sustained wind speeds of a tropical cyclone of at least 35 miles per hour within 24 hours. So there's a lot of wind in a very short amount of time. And and we know that for a hurricane form, we need a couple of things. We need a pre existing weather disturbance and low wind shear. So that means that there's not much change in the wind speed or direction over where the storm is. You need sea surface temperatures of at least 80 degrees Fahrenheit over a depth of 150 feet. That's going to be very important with the rapid intensification part. And you also need an area of thunderstorms, because you need something for everything to really get kicked off. And researchers are diving into why storms try and do intensify so quickly. And NCAR they found two modes of rapid intensification. The first one is when a hurricane starts to intensify symmetrically, so once you start to see that storm basically becoming very circular, that is when you have to get quite concerned. And this typically happens when there's plenty of warm water and low wind shear. Hurricanes Andrew and Katrina. We know those names, perfect examples of this. And last year we saw hurricane Otis. The wind speed in that storm increased by 110 miles per hour in 24 hours before hitting Mexico's West Coast as a Category five storm. That storm was beyond most forecasts. So that is why we're working so hard to find out why this kind of intensification happens.
BB: 110 miles and hour in 24 hours. That's staggering.
TA: That is incredibly scary. The second manner of rapid intensification occurs when there are significant bursts of thunderstorms happening away from a storm center. So you have the explosion of thunderstorms occurring in that storm, and that allows it to basically reconfigure its circulation. And while it may not become a cat three, cat four, a cat five, it can easily become a cat one, cat two, within a couple of hours in that type of scenario, and that in its own can be incredibly dangerous. So of course, we're gonna have to keep an eye on that, because this can happen in situations where you have strong wind shear, or even not as strong or not as warm water. So it happens in situations where you're not paying as much attention to it, and that can catch people off guard pretty quickly. Now, this method of intensification is not guaranteed, because only 10% of storms going through this process in unfavorable environment will actually intensify this way. So it's rare, but it happens, and we want to make sure that we're keeping an eye on it.
