Earth and Atmospheric Sciences, Department of
Date of this Version
2007
Abstract
Preliminary schematics of polarimetric signatures are developed for classic, tornadic supercells at low, mid, and upper levels for the Southern and High Plains. Schematics are developed for pre-tornado, tornado, and tornado demise times from a small collection of cases, most of which were cyclically tornadic. Characteristic signatures and patterns are identified for reflectivity factor (ZHH), differential reflectivity (ZDR), correlation coefficient (ρhv), specific differential phase (KDP), and linear depolarization ratio (LDRVH), and signatures likely related to the tornado lifecycle are discussed.
Additionally, observed changes in four polarimetric variables (ZHH, ZDR, ρhv, and KDP) and radial velocity are presented through the tornado lifecycle for three Southern Plains classic supercell cases, and evolution possibly related to tornado genesis and demise is discussed.
Primarily, the information presented herein should be useful for nowcasters as they use real-time polarimetric radar data to identify supercells and associated threats, notably the presence of large hail, tornadoes, and heavy rain. This information should also be useful in helping nowcasters interpret real-time evolution of the polarimetric variables in supercell storms, and may improve severe weather warnings, especially after the polarimetric upgrade to the national radar network.
Comments
A THESIS SUBMITTED TO THE GRADUATE FACULTY UNIVERSITY OF OKLAHOMA GRADUATE COLLEGE in partial fulfillment of the requirements for the Degree of MASTER OF SCIENCE, Norman, Oklahoma 2007
© Copyright by MATTHEW SCOTT VAN DEN BROEKE 2007