Mountain Wave Clouds

This morning as the upper low and storm system exited the region. Strong northwest flow moved in and we got 2 distinct types of mountain wave clouds. Which can be seen from the visible satellite.


There are some pretty neat things going on here when you take a look at the surface winds at 10m(image left below) and then take a look at the vertical velocities(image right below). You can see in the wake of the mountains we have some lift in the green areas which is indicative of lee mountain rotors.

Surface Winds                                     700mb Vertical Velocities


If you look closely you see 2 types of cloud formations. One is a mountain wave pattern over Virginia and West Virginia and also visible in the northern mountains of North Carolina near Boone. If you look further south you can see cirrus clouds coming off the mountains of Southern North Carolina the upstate of South Carolina into NE Georgia.

Wave Clouds                                                Cirrus Clouds


What is going on here is some chaotic vertical motions caused by the departing low pressure system interacting with the mountains. Moisture at high levels & mid-levels along with cold dry surface air make for some cool cloud formations. Here’s a diagram of the process. You can see how the lee side turbulence and rotors cause the wave clouds but also how those rotors can create higher level cirrus clouds downwind of the mountains.

System Mountain Wave - Rotor