A Climatology of Mesoscale Airmasses with High Theta-e Across the Continental United States

A Mesoscale Airmass with High Theta-E (MAHTE) is a narrow region of larger theta-e located on the cool side of an airmass boundary. MAHTEs typically possesses higher CAPE than the warm side of the boundary, creating a more favorable environment for severe convection. MAHTEs can also be characterized by larger low-level shear and lower LCLs and may also have a propensity for supporting tornadogenesis. The majority of MAHTE research to date has been comprised of case studies, but the prevalence of MAHTEs is not well understood. This project fills that knowledge gap by creating a climatology of MAHTE occurrence. This climatology has been created through the identification of MAHTEs in time series of ASOS data from across the continental United States. The identification algorithm has been verified using West Texas Mesonet data, providing high temporal and spatial resolution that the ASOS network cannot achieve. MAHTEs from over 1000 ASOS stations have been identified and compiled into a national climatology. Further analysis of results will explore the spatial, diurnal, and seasonal distribution of MAHTE occurrence, and investigate which type of parent airmass boundary is most favorable for MAHTE formation.