Perhaps my earliest childhood fantasy was wishing to build a castle in the clouds, and to this day I am fascinated by the ever-changing cloudscapes when I fly.I finally decided to do a little cloudology, and I hope you enjoy the fruits of my labor today (and if I don’t get distracted, tomorrow too).(Stratus nebulosus, used by permission of Daniel Andrist)
Clouds are classified according to their shape, their altitude, and their potential for bringing rain (and a zillion other things beyond the scope of this essay), using words with Latin root meanings. The three basic shapes are 1. “stratus” (which means “layer or covering”). They look like a soft, wooly blanket covering the earth (as pictured above) and are low-hanging (under 6,500 feet).
2. “Cumulus” (which means “heap”), are the fluffy white clouds bouncing along on a sunny afternoon that are fun to count and continuously change shape. They are also low clouds, usually breezing along at under 6,500 feet.3. “Cirrus” (which means “curl”) are the wisps of cloud that look like strands of hair. My mother used to call them “mares’ tails.” They are also the highest clouds in the sky, forming at over 20,000 feet, and are made of ice crystals.(cirrus above altocumulus clouds)
There are also three classifications for clouds based on altitude: 1. Low-Level (up to 6,500 feet into the atmosphere), 2. Mid-Level (between 6,500-20,000 feet), and 3. High-Level clouds (20,000+ feet). Low-hanging cumulus and stratus clouds do not have a prefix, but mid-level clouds use the prefix “alto” and high-level clouds use the prefix “cirro.” Because we were approximately 32,000 feet in the air when this picture was taken, I’m assuming these clouds are cirrus (high, wispy) clouds above altocumulus (mid-range puffy) clouds.
There’s also such a thing as an altostratocumulus cloud, which is a mid-level cloud that has formed a blanket of cumulus clouds that are all crowded together in rows, looking almost like crooked furrows of earth ready for the planting.
The last simple classification for clouds has to do with whether or not they are likely to produce rain. There are two major “rainclouds.” We notice the nimbostratus clouds on grey, overcast days when “it looks like rain” outside so we either stay at home or pack an umbrella in anticipation of a long, drizzly battle against wetness (or—if you live up north and it’s winter—snow)!The second type of raincloud is the towering cumulonimbus. These mighty monsters move in fast and ominously, and unless you thought to catch a weather report before you left home, you’re likely to get caught in a flashy downpour.
“You know how to interpret the appearance of the sky, but you cannot interpret the signs of the times…” (Matthew 16:3) (I’m still trying to learn both! 🙂 )