An Analysis of Vortices Embedded within a Quasi-Linear Convective System Using X-Band Polarimetric Radar

作者：Mahale Vivek N^*; Brotzge Jerald A; Bluestein Howard B

来源：Weather and Forecasting, 2012, 27(6): 1520-1537.

DOI：10.1175/WAF-D-11-00135.1

On 2 April 2010, a developing quasi-linear convective system (QLCS) moved rapidly northeastward through central Oklahoma spawning at least three intense, mesoscale vortices. At least two of these vortices caused damage rated as category 0 to 1 on the enhanced Fujita scale (EF0-EF1) in and near the town of Rush Springs. Two radar networks the National Weather Service Weather Surveillance Radar-1988 Doppler network (WSR-88D) and the Engineering Research Center for Collaborative Adaptive Sensing of the Atmosphere (CASA) radar network collected high spatial and temporal resolution data of the event. This study is an in-depth polarimetric analysis of mesovortices within a QLCS. In this case study, the storm development and evolution of the QLCS mesovortices are examined. Significant findings include the following: 1) The damage in Rush Springs was caused by a combination of the fast translation speed and the embedded circulations associated with QLCS vortices. The vortices%26apos; relative winds nearly negated the storm motion to the left of the vortex, but doubled the ground-relative wind to the right of the vortex. 2) A significant differential reflectivity (Z(DR)) arc developed along the forward flank of the first vortex. The Z(DR) arc propagated northeastward along the QLCS with the development of each new vortex. 3) A minimum in the copolar correlation coefficient (rho(hv)) in the center of the strongest vortex was observed, indicating the likely existence of a polarimetric tornado debris signature (TDS). A secondary rho(hv) minimum also was found just to the right of the vortex center, possibly associated with lofted debris from straight-line winds.

• 出版日期2012-12