 Complete the following phrase:  Before the Greensburg EF5 tornado on May 4, 2007, it had been eight years and one day since the United States had a confirmed F5EF5 tornado. Prior to Greensburg, the last confirmed F5EF5 had hit the southern Oklahoma City metro area and surrounding communities on May 3, 1999. This stretch was later surpassed by an ongoing drought which began on 