Straight-line wind vs. tornadoes

AccuWeather's Bernie Rayno explains the difference between damaging straight-line winds and tornadoes.

Transcript

00:00And severe weather racing across Mississippi and Louisiana this morning.

00:09The main threat and what we've been seeing damaging winds and tornado.

00:13The ingredients are somewhat similar for both, but there are some differences and that's

00:19why you get different phenomena like damaging winds and tornadoes.

00:23Now damaging straight line winds is where you have the increasing wind with height.

00:29You see that with tornadoes as well, but here's the difference.

00:31The wind direction is the same from the surface to the upper part of the atmosphere.

00:37And when you get that, oftentimes you get a push of air out ahead of the line of thunderstorms

00:42where you could have damaging wind gusts and even downbursts.

00:47What happens is some of the rain that falls from the cloud evaporates.

00:51That's a cooling process and that forces the air down and then it accelerates outward.

00:57Now the ingredients for tornadoes, somewhat similar as straight line winds.

01:02You get the increasing wind with height, but here's the main difference.

01:06Not only do you get an increasing wind with height, but you get the change of wind direction

01:10with height coming in, let's say out of the southeast at the surface, west, northwest

01:15a lot.

01:16So that changing wind direction, what does that do?

01:19It causes the air to rotate in the horizontal.

01:23So you get this rotating column of air within the horizontal because of that wind direction,

01:29that change direction with height.

01:31Then updrafts takes the horizontal rotation and makes it more vertical.

01:37And of course, the stronger the wind shear, the stronger the updraft, the stronger the

01:42tornado, but that's the difference between straight line winds and tornadoes.

01:50It's all about the change of wind direction with height.

01:53And now you know, stay with us.