The National Weather Service (NWS) recorded 7.4 inches of snowfall in Sioux Falls, South Dakota, by the morning of Friday, December 9.An “unusual” storm hit the southeastern part of the state, combining heavy snowfall with thunder and lightning, the NWS reported on Thursday.Video posted by the NWS Sioux Falls on Thursday shows fluffy flakes falling on snow-covered grounds.The NWS warned people to prepare for “widespread rain” next week, which “could lead to street flooding.” Credit: NWS Sioux Falls via Storyful