A dancer doing various locking moves. Locking is a style of funk dance, which is today also associated with hip hop. The name is based on the concept of locking movements, which basically means freezing from a fast movement and locking in a certain position, holding that position for a short while and then continuing in the same speed as before.
A tornado warning is worse. It means that a tornado has been detected or the threat of one is imminent. A tornado watch means the overall conditions are favorable to form in a general area.
A severe thunderstorm warning, on the other hand, is not issued until such a storm has been physically observed or is spotted on radar. A tornado watch is issued when conditions may produce a tornado, and a warning is issued when a tornado has been sighted, or when rotation is seen on radar.