May 2017 Photo

Rain Cloud

May's calendar image, "Rain Cloud," was shot from the Evanston shore. This cloud formation contains several interesting meteorological elements: The overall structure is often called a Thunder Head, the highest clouds stretched out in a thin layer are called an Anvil, and the small ball-like clouds on the underside are known as Mammatus Clouds (something I just learned myself!). The hazy part extending down to the horizon is a Rain Curtain — formed by, you guessed it, falling rain.