Gravity Waves

Do you know what's causing the clouds to line up in uniform rows like these pictures show?

That was the scene I snapped outside the station in Austin around 6:45pm this evening (Tuesday).

It's a Gravity Wave and it's basically a sign of oscillating momentum in the atmosphere.

Here's how gravity waves form.  Just like a wave you'd see in water from a tossed stone, a vertical disturbance in the atmosphere is needed to create lift, like topography from a mountain or more likely in this instance updrafts from a weak pocket of unstable air.

The air is moved upwards and once it encounters a layer of stable air, it loses it's upward momentum and begins to sink back down due to gravity. As the air is lifted it saturates and condenses out to form a cloud.  Then, in this instance, as the air begins to sink the cloud dissipates leaving the sky clear.

Sometimes you can see visible lines of clouds on a satellite image as shown below.


In this evening's instance there was another deck of clouds obscuring the view of the satellites. 

However, some gravity wave scenarios will be completely overcast leaving the entire wave visible in the cloud.  It's tough to see with the naked eye but these clouds do produce a wave like motion.  If you were able to take a timelapse of this you would see a slow, fluid motion of the clouds rising and falling back down.  Just like this REALLY COOL timelapse of a more pronounced gravity wave event recorded in Tama, Iowa back in 2007.

For more information on what gravity waves are and how they form... click here.

Storm Tracker 6 Chief Meteorologist
Chris Kuball