A Radar Study of the Dominant Tornadic Supercells that Traversed Parts of the Ohio Valley and New York City on 16 September 2010

Tornadoes caused significant damage across parts of Ohio, West Virginia, and New York City on 16 September 2010. GR2Analyst will be used to evaluate the dominant tornadic supercells with base and derived WSR-88D Level II radar products, using 2D plan views, cross sections, and 3D volumetric displays.

GR2Analyst is a PC-based application from Gibson Ridge Software for analyzing live and archived WSR-88D Level II radar imagery. In addition to standard Level II radar products (base reflectivity, base velocity, storm relative velocity), GR2Analyst produces high resolution reflectivity-derived graphical products, including Normalized Rotation (NROT). Volumetric displays of the base products and NROT as opaque and semitransparent surfaces are possible, and an interactive slider is available for drilling through volumetric isosurfaces to fine tune the display of 3D physical and flow-related features. In particular, this study will concentrate on 2D plan views, cross sections, and 3D volumetric displays of base products and NROT, and careful manipulation of displays will reveal the juxtaposition of storm-related physical (base reflectivity) and flow-related (base velocity, storm relative velocity, NROT) features.

Severe storms developed ahead of a cold front on 16 September, part of a surface system associated with a well defined mid level trough that tracked eastward across the eastern Great Lakes during the afternoon and evening hours. Preliminary reports indicate 19 tornadoes, 56 high wind reports, and 24 Hail reports across parts of Ohio, West Virginia, New Jersey, and New York City. Radar detection and warning methods are evolving rapidly as a function of progressive technological advances. This presentation highlights some of the methods that will become increasingly important as the National Weather Service moves toward Phased Array Radars.