F1 tornado in Muskogee County, Oklahoma

An F1 tornado touched down near the Port of Muskogee and moved south for 2.25 miles, lifting just south of Three Forks Park. This tornado destroyed three structures belonging to one business, destroyed two business outbuildings at 3-Forks Park, caused minor damage to one business under construction, and affected eight single family dwellings. The most newsworthy result of this tornado was damage directly inflicted upon the OG&E electrical generation plant. The tornado damaged a coal conveyor belt and a cooling tower. The damage was enough to shut down two of the plant's four coal-powered generating units. At the Fansteel plant, six buildings were torn down by the tornado, causing up to $1.5 million damage there.

Summary of events for the afternoon and evening of June 1 1999:A cold front moving in from the northwest moved into an extremely unstable air mass on the afternoon of June 1. Along the front, an isolated supercell thunderstorm developed around the Pryor/Locust Grove area and then moved in a slow and unusual south-southwest direction. This storm produced very large hail in addition to several strong tornadoes. This storm also produced eastern Oklahoma's first killer tornado in at least half of a decade.