Project Vortex-99. Occluded mesocyclone tornado.
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 #3 of sequence.
Image ID: nssl0210, NOAA's National Severe Storms Laboratory (NSSL) Collection Location: Oklahoma 7 miles south of Anadarko Photo Date: May 3, 1999 Credit: OAR/ERL/National Severe Storms Laboratory (NSSL)