Rotational velocity
Notes:
The data on this slide shows time trends of rotational velocity prior to tornado touchdown at 0.5 degrees (blue), 0.9 degrees (red) and 1.5 degrees (green). Note the very rapid development of strong rotation at 0.5 degrees, just prior to tornado touchdown (marked by the "T").Smaller values of rotation developed at higher scan elevations, concurrently with the development of low-level rotation.
Slide 20