The prestorm environment of the 20 May 2013 Moore, Oklahoma Supercell estimated from WSR-88D and TDWR radar, and GOES satellite data

On May 20th 2013, a large violent tornado devastated the Moore area in central Oklahoma about 20-21:30 UTC. An outlook of a significant severe storm outbreak had been issued a few days in advance by the NOAA Storm Prediction Center. The region of central Oklahoma was under a moderate high risk of severe storms on the morning of the 20th. A tornado watch issued about an hour before the storm developed. Based on model forecasts from the morning of the 20th,the greatest risk of violent tornados appeared to be in south-central OK. While supercell storms did develop in that area, they did not produce intense tornadoes as was the case further north.

The supercell associated with the Moore tornado appeared to intensify rapidly near a surface boundary as detected on radar and satellite. The propagation speed of several convective elements on radar suggested mid-level level winds exceeding that analysed earlier in the day. These two observations served as motivation to examine the wind structure of the near-storm environment for unique factors unavailable in the operational analysis. The wind structure will be examined from WSR-88D and TDWR Doppler radar, GOES satellite, surface mesonet data, and available upper soundings. Output from the variational LAPS analysis system developed at the ESRL/GSD, and from a 3-D variational analysis with advanced radar quality control capability developed at the NSSL, will be presented and compared with the operational analysis for this severe weather event.