Project Vortex-99. An occluded mesocyclone tornado rated an F3 by an NWS damage survey. Occluded means old circulation on a storm; this tornado was forming while the new circulation was beginning to form the tornadoes which preceeded the F5 Oklahoma City tornado. Photo #1 of sequence.

Image ID: nssl0208, NOAA's National Severe Storms Laboratory (NSSL) Collection
Location: 10 mi. south of Anadarko, Oklahoma
Photo Date: May 3, 1999
Credit: OAR/ERL/National Severe Storms Laboratory (NSSL)

• High Resolution Photo Available