The National Weather Service said the preliminary storm estimate for Wednesday night's tornado in Granbury was an EF-4, based on the Fujita tornado damage scale. That means the storm carried wind speeds of 166 mph to 200 mph.
The NWS believes 10 tornadoes raked North Texas in a violent system, including the one in Granbury, about 40 miles southwest of Fort Worth. Other tornadoes damaged nearby Cleburne and Millsap.
Forecast Jesse Moore says NWS teams traveled to the affected cities Thursday to survey the damage and speak with emergency management officials.
He says more than one tornado might have touched down in various areas.