Latest Oklahoma tornado 'widest ever' In this May 31, 2013 file photo a tornado forms near Banner Road and Praire Circle in El Reno, Oklahoma. The National Weather Service says the deadly tornado that struck near Oklahoma City late last week was another top-of-the-scale EF5 that packed winds reaching 475 km/h. THE deadly tornado that struck near Oklahoma City late last week had a record-breaking width and was another top-of-the-scale EF5 that packed winds reaching 475 km/h. The National Weather Service initially rated the Friday tornado that hit El Reno as an EF3. But the agency upgraded the ranking after surveying damage from the tornado, which along with subsequent flooding killed 18 people. The weather service also determined the twister was 4.2 kilometres wide, the largest ever recorded. The update means the Oklahoma City area has seen two of the extremely rare EF5 tornadoes in only two weeks. The other hit the city of Moore on May 20, killing 24 people and causing widespread damage. Friday's massive tornado avoided the highly populated areas near and around Oklahoma City, and forecasters said that likely saved lives. When the winds were at their most powerful, no structures were nearby, said Rick Smith, chief warning coordination meteorologist for the weather service's office in Norman. Any house would have been completely swept clean on the foundation. That's just my speculation," Mr Smith said. We're looking at extremes ... in the rare EF5 category. This in the super rare category because we don't deal with things like this often. The EF5 storm that hit Moore decimated neighbourhoods. In Friday's storm, many of the deaths were caused by heavy flash flooding following the storms. Three storm chasers died in that storm. Mr Smith said the storm's 4.2-kilometre path - besting a record set in 2004 in Hallam, Nebraska - would have made the storm hard to recognise up close.