Interactions between Mesocyclones and Wave Anomalies: Three Case Studies

Several case studies of mesocyclone interaction with wave-like features are investigated for their effects on tornadogenesis. In these case studies, strong tornadoes form when wave/mesocyclone interaction occurs. Using a combination of Doppler radar and Dual-polarization radar, three case studies are examined in great detail. In several instances, wave-like formations can be seen on base velocity and composite imagery propagating in directions unlike the storms themselves. All interactions with these waves appear on the south southeastern side of the mesocyclone. It is hypothesized that a passing wave will stretch the column, temporarily increasing rotational speed within the mesocyclone. This temporary increase in rotational speed, along with other atmospheric variables, appears to help in the development of strong tornadoes. Subsequent waves passing by the same mesocyclone appear to enhance vorticity as detected by radar imagery. Storms investigated in these case studies produced tornadoes rated F/EF4 and appear to be the southernmost storms in a series or QLCS. Careful consideration was taken to eliminate any other variables, such as horizontal convective rolls and outflow boundaries that might otherwise interfere with the understood interactions. In each case, strong tornadoes formed as a result of mesocyclone/wave interactions.