Altocumulus clouds with the sun behind them.

I was following my son-in-law around on a golf course the other day. He was looking down for his golf ball, and I was looking up at these neat altocumulus clouds with the sun behind them.

Altocumulus clouds

With the sun at a different angle, the clouds looked a bit different. Their flat pancake-looking shape can be seen.

Altocumulus clouds form at medium altitudes (6,000 to 20,000 feet). Their name is a combination of “alto” meaning high (same root as “altitude”) and “cumulus meaning “mass or heap” (same root as “accumulate”). They are composed of supercooled water droplets or ice crystals. Precipitation does not normally occur from these clouds, but if it does, it evaporates before reaching the ground. Sometimes a shaft of precipitation, called virga, can be seen trailing from these clouds for a short distance before it evaporates into the atmosphere.