Normalized rotation - Erin tornado
Notes:
The data on this slide shows GR2 analyst-calculated normalized rotation at 0.5, 0.9 and 1.4 degree elevation angles for the storm that produced the tornado in Erin, New York. In this case, the rotation increased simultaneously at all 3 elevation angles, then fell at all 3 elevation angles just prior to tornado touchdown. The decrease in rotation appeared to occur slightly earlier at 1.4 degrees and 0.9 degrees, with a one volume scan lag in the decrease noted at 0.5 degrees.
Slide 27