Doing the Wave
We received another fun weather factoid from the AB-Tech Institute for Climate Education today. You can see some of their other interesting stories we've covered here and here.
|Doing the Wave: Pamela McCown|
You may have noticed a significant change in our skies yesterday afternoon as fair skies turned cloudy. These clouds moved in from the west late in the day ahead of the system that brought showers overnight and more significant rain into the region this afternoon.
I noticed an interesting feature to the clouds... waves. The waves are caused by the interaction of the air with the complex terrain in the mountains and they occur fairly regularly, especially in the fall, winter and early spring as storm systems approach from the west. The clouds in the picture are called Altostratus Undulates.
Meteorologists classify clouds using three main criteria:
-Height of the cloud base
-Whether or not the cloud is producing precipitation
In this case, the clouds were at mid-level (6,500 – 20,000 ft.). So, they are given the name Alto – meaning mid. Their shape is like that of a sheet or blanket. So, they are called Stratus – meaning layer. And, you can recognize the word undulate, meaning wavy. (Scientists love to use Latin to classify things – even clouds!)
Interested in learning more – check out the classes that the Institute is offering this winter, here. You’ll learn how to read the sky and become aware of changes to the weather!
Remember, the Institute is holding a free public seminar on Tuesday, December 6th at 6:00 p.m. when Meteorologist Tom Ross will present The Long Range Winter Forecast for Western North Carolina.
November 21, 2011