Unconventional evolution of the mesoscale convective system (MCS) of May 23 during MC3E

On the afternoon of 23 May 2011, a line of severe thunderstorms developed along the dryline and approached the dense observing array centered on the DOE Southern Great Plains Central Facility in Oklahoma. Many strong to severe thunderstorms were observed by multiple surface-based radars, and by aircraft, providing one of the best opportunities for detailed coordinated study of the field campaign. This presentation includes examples of overpasses of these thunderstorms by the radar and passive microwave instruments on board the NASA ER-2, providing opportunities for estimating vertical motions from aircraft, and also from surface-based radars and profilers. Cloud microphysics data from the UND Citation obtained in stratiform precipitation regions very close to the convective cores are also shown. Despite the strength of the convective storms, the system did not evolve as might have been expected into a large MCS. New convection failed to organize into a leading line - trailing stratiform squall line system, but rather had elements of both forward and backward propagation, and strong interactions with cold pools from pre-existing MCSs. These interactions are described to place the life cycle of this system into the context of its mesoscale environment.