Observational analysis of the interaction between a baroclinic boundary and supercell storms on 27 April 2011
Date of Award
Master of Science (MS)
Larry D. Carey
Baroclinic models., Tornado warning systems., Thunderstorm forecasting., Tornadoes.
A thermal boundary developed during the morning to early afternoon hours on 27 April as a result of rainfall evaporation and shading from reoccurring deep convection. This boundary propagated to the north during the late afternoon to evening hours. The presence of the boundary produced an area more conducive for the formation of strong violent tornadoes through several processes. These processes included the production of horizontally generated baroclinic vorticity, increased values in storm-relative helicity, and decreasing lifting condensation level heights. Five supercell storms formed near and/or propagated alongside this boundary. Supercells that interacted with this boundary typically produced significant tornadic damage over long distances. Two of these supercells formed to the south (warm) side of the boundary and produced a tornado prior to crossing to the north (cool) side of the boundary. These two storms exhibited changes in appearance, intensity, and structure. Two other supercells formed well south of the boundary. These two storms remained relatively weak until they interacted with the boundary. These storms then rapidly intensified and produced tornadoes. Supercells that formed well into the cool side of the boundary either did not produce tornadoes or the tornadoes were determined to be weak in nature.
Sherrer, Adam Thomas, "Observational analysis of the interaction between a baroclinic boundary and supercell storms on 27 April 2011" (2014). Theses. 57.