The National Weather Service says a tornado that swept through Joplin, Mo., and killed at least 116 people packed winds up to 198 mph.

The weather service's director, Jack Hayes, says the storm was given a preliminary label as an EF4 - the second-highest rating given to twisters. The rating is assigned to storms based on the damage they cause.

Hayes said the storm had winds of 190 to 198 miles per hour. At times, the storm was three-quarters of a mile wide.

He says survey teams from the National Weather Service are on the scene and will make a final determination on the rating Tuesday.

A tornado outbreak last month killed more than 300 people across the South. At least three of those storms were rated EF5.