Prevalence and Characteristics of Atmospheric Waves in Severe Weather Environments

Interactions of weak, wave like reflectivity segments (WRS) with convection appear to be a common feature in severe weather environments. This is important since their interactions with convection are often followed by increases in severe weather, such as tornadoes. For example, Barker (2006) found a link between “reflectivity tags” (which were assumed to be waves) that moved quickly through linear convection and were associated with tornadogenesis. Coleman and Knupp (2006) documented mergers between linear features in radar reflectivity factor Z (whose motion was consistent with gravity waves) and convection that were temporally correlated with an increase in mesocyclone rotation or tornadogenesis. Coleman and Knupp (2008) used a simple model and corroborating observations to show how ducted gravity waves, upon interaction with mesocyclones, could increase the vertical vorticity of the low-level mesocyclone.

Barker (2006) speculated the WSR-88D upgrade to build 10/super-resolution has aided in the identification of weak Z features that may be waves. While these features appear to be common, there has yet to be a full investigation into the prevalence of atmospheric waves in severe storm environments, which is the primary purpose of this research. This presentation will show preliminary results and statistics on the frequency of atmospheric waves in the severe storm environment. This includes an investigation of suspected wave type and the environmental characteristics where the waves form. A secondary objective includes an exploration of the radar characteristics of the waves, such as horizontal and vertical extent and Z profiles. It is important to note the radar differences between suspected waves and ordinary convective cells, especially considering the operational importance of identifying waves in the severe storm environment.