Those storms want a lot of shear. Wind going in different directions and different speeds with height.

龙卷风雷雨需要大量的风切变。风切变指，风吹向不同的方向，风速随高度而变化。

We hear about it in tornadic thunderstorms. Those storms want a lot of shear, wind blowing in different directions and different speeds with height.

我们在龙卷风的雷暴中听说过。这些风暴想要很多很多的切变，在一定高度上风会在不同方向以不同速度吹开。