Recorded presentation5B.4
Kinematic structure and evolution of the 9 March 2006 Mississippi/Alabama bow echo
Calvin Elkins, University of Alabama, Huntsville, AL
This study investigates the characteristics of the 9 March 2006 Mississippi/Alabama bow echo system (mesoscale and synoptic) during its most intense phase, with special attention given to the kinematic structure and evolution of the system. On 9 March 2006, a severe cold season squall line formed over Louisiana and intensified just east of Columbus, MS, near the Mississippi – Alabama border, where it assumed a bow echo configuration and produced a long swath of damaging winds from eastern Mississippi to northern Alabama. While the storm exhibited several familiar earmarks of cold-season bow echoes, questions still remain as to why the bow formed exactly where it did and why it evolved from bow to break so quickly. The data was gathered through Single-Doppler and synthetic dual-Doppler analyses. Comparison of the two data sets showed strong agreement. Analysis of the event shows a strong similarity to previously assumed parameters of cold-season quasi-linear convective systems. Dynamic forcing caused strong updrafts but were accompanied by apparently weak downdrafts. A strong cold pool existed along with a well-defined rear-inflow jet and mesovortices (both mesoscale and convective scale). This study highlights the need for more research in the area of cold-season QLCS's, specifically their structure and evolution. The resulting wind fields will be used to examine relative magnitudes of buoyancy, pressure forcing and loading within the convective updraft and downdraft.
Session 5B, Severe Weather I
Tuesday, 6 October 2009, 8:30 AM-10:00 AM, Room 18
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