The Central Oklahoma Tornado Outbreak of May 03, 1999


Overview: The May 03 event seemed to be a worst case scenario in terms of threatening lives and property.  The National Weather Service(NWS) has, thus far, identified 8 supercell thunderstorms which produced 59 discernable tornadoes in Central Oklahoma alone.  Many of these tornadoes were violent, longtrack, and struck cities directly, including heavily populated Oklahoma CIty.

Public Warning: One of the silver linings to May 03, is the efficiency at which official tornado warnings were relayed to the public.  The unique concentration of weather resources in Central Oklahoma undoubtedly saved lives.  Storm spotters, including the NSSL VORTEX crew, and media severe weather coverage provided timely, accurate information to the NWS, and, in turn, the public.  The long track nature of the more violent tornadoes also allowed for very early warning.

WDSS:  WSR-88D data, however, is the primary tool for the NWS forecasters when dealing with severe weather.  The Norman NWS Forecast Office is a test site for WDSS, a package of severe weather detection algorithms and special display software developed at NSSL.  WDSS was in operation on May 03.  This case study will focus on the performance of the NSSL Mesocyclone Detection Algorithm (MDA), the NSSL Tornado Detection Algorithm (TDA), and the NSSL Bounded Weak Echo (BWER) algorithm, as well as a WRS-88D overview of the storms.

Follow these links for background information on the NSSL MDA and NSSL TDA.

Storm A - The Oklahoma City Supercell
Storms B,G - Anadarko to Mulhall, El Reno to Mulhall
Storm D - Pink to Shawnee to Stroud
Storms C,E,H,I - The Dover Storm and Others

Summary of WDSS Algorithm Performance

More Information on the May 03. 1999 Event

National Weather Service Forecast Office - Norman, Oklahoma
Travis Smith's May 3 Radar Page
Information the Warning Decision Support System (WDSS)
Information on the VORTEX project