A Modeling Study of Supercell Development in the Presence of a Preexisting Airmass Boundary
Jennifer M. Laflin, Adam L. Houston
Abstract
Airmass boundaries have been documented as a major influence on convective initiation and development, particularly in supercell thunderstorms. Therefore, this study seeks to determine the specific influence of an airmass boundary on supercell development through idealized numerical modeling. To do this, convective initiation is simulated in an environment that represents a case where supercells were observed forming along a preexisting airmass boundary. Three simulations are conducted, which illustrate convective initiation in the warm sector, cool sector, and along the airmass boundary. Deep convection occurs in all simulations; however, a steady-state supercell is only produced in the boundary simulation. Analysis of these results reveals that the airmass boundary supports supercell formation and development by increasing the strength of the updraft, creating and supporting a low-level mesocyclone, and enhancing the gust front. In this study, the airmass boundary is found to have a profound impact on the simulated storm, and is necessary for supercell development and longevity even with an ambient environment that supports supercells.
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Citation:
Laflin, J. M., and A. L. Houston, 2012: A modeling study of supercell development in the presence of a preexisting airmass boundary. Electronic J. Severe Storms Meteor., 7 (1), 1-29.
Keywords:
supercells, storm environments, mesoscale processes, numerical simulations, mesocyclones, convective-scale processes