St. Louis, MO – A severe thunderstorm watch has been issued for parts of Kansas, Missouri, and Oklahoma until 11 PM CDT Saturday. According to the US National Weather Service Saint Louis, the affected areas include Jefferson City, Joplin, Springfield, and parts of northern Oklahoma. The watch indicates the potential for isolated hail up to the size of a ping pong ball, scattered wind gusts reaching up to 75 mph, and frequent lightning.