One person was killed by a tornado, on Monday afternoon.
The tornado struck outside Wynnewood, Oklahoma.
Six more people were injured and a dozen buildings were destroyed by the twister.
A second death was also reported, due to the storm, but authorities said it was not because of the tornado.
Several other tornadoes struck elsewhere in Oklahoma and Kansas.
Hail as large as four and a quarter inches in diameter accompanied the storm.
The storm threat will continue into the night, for Oklahoma, Kansas, Texas, and Arkansas.