Strong thunderstorms passing through parts of Oklahoma have brought large hail, strong winds and lightning but apparently no tornadoes.

The National Weather Service issued only one tornado warning on Saturday night, for parts of Beaver County in the Panhandle. Amarillo, Texas-based weather service meteorologist J.J. Brost said that it was difficult to tell if a twister actually formed because of heavy precipitation.

Brost says the storm did produce hail stones the size of tennis balls near Forgan.