The NOAA's National Weather Service released the service assessment for the May 3, 1999 Oklahoma/Southern Kansas Tornado Outbreak today. Service assessments are a routine internal review of weather service operations during major severe weather events.

During the May 3, 1999 event around 70 tornadoes, many of them rated as severe F3 tornadoes with winds of 158-206 mph, were spawned by a dozen supercell thunderstorms across Oklahoma and southern Kansas. The most dramatic of these tornadoes was an incredible F5 tornado with winds of 261-318 mph which devastated densely populated areas of Oklahoma City and its suburbs, leaving 38 people dead and causing over $1 billion in damage.