It's 4:30 on the afternoon of Saturday, December 30, 2017. The temperature is -6 degrees Fahrenheit. After yesterday's 3.4" snowfall in Cedar Falls, Iowa the stage is set for a very cold night of sub-zero readings. Overhead a patch of clouds is drifting to the southeast. The first photo shows altocumulus clouds in the southwestern sky. The second photo is looking south at altocumulus in the top portion of the photo with altostratus covering the bottom.
The Weather Briefing Blog