174 When Supercells Move Right, but Tornadoes Move Left: Observations from Two Episodes of Tornadogenesis after the Occlusion of their Parent Mesocyclone during the Alabama-Georgia Tornado Event of 19 March 2017

Thursday, 25 October 2018
Stowe & Atrium rooms (Stoweflake Mountain Resort )
Kyle J. Thiem, NWS, Peachtree City, GA; and S. E. Nelson

On 19 March 2018, a Quasi-Linear Convective System with embedded, cyclic, tornadic
supercells moved through Alabama and Georgia producing several tornadoes and
damaging wind swaths, including an EF-3 that went through Jacksonville, AL. While the
most significant damage occurred in Alabama two very short-lived tornadoes touched
down in Georgia from an associated, easterly-moving supercell. The first took a southerly
track through Buchanan, GA and caused EF-1 damage and injured two people. The
second took a southwesterly track and caused EF-2 damage to a two-story residential
neighborhood NW of Fairburn, GA. Tornado damage surveys revealed both tornado
tracks were less than 2 miles and lasted only a few minutes, however, each had occurred
several minutes after the rear-flank gust front had occluded the associated mesocyclone
which had then begun a cycloidal loop back towards the rear of the storm and appeared to
have weakened. This study documents the unique evolution of this supercell during these
two episodes of tornadogenesis.
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