Curtis sez, "My mom lives in Joplin, MO and while out doing some work on the house in the morning saw these crazy clouds in the sky. Unfortunately, she didn't have a camera. Fortunately, the local news did. According to the weatherman on TV, they are called 'lenticular mammatus' and occur infrequently. The last reported sighting in the area was about 30 years ago."
Link
(Thanks, Curtis!)
Update: Scim sez, "In the post the clouds were called 'lenticular mammatus', which I don't
think it a real term, though each term by itself is a real cloud name.
Lenticular clouds, meaning lens shaped, are rounded and have been mistaken
for UFOs before. Mammatus clouds are called such because the hanging
pouches of the clouds resemble mammary glands (like a cow's udders)."
