Elevated Convection: Radar Signatures and Observations Associated with Gravity Wave-Breaking Damaging Winds

A growing number of cases in which evenly-spaced elevated convection coincident with gravity waves have been identified and cataloged. Nearly half of known cases are associated with unexpected damaging surface wind production including a non-negligible number with particularly dangerously damaging winds greater than 33.5 ms-1 (75 mph) posing a keen forecasting and operational warning challenge. In each of the damaging cases, the strongest surface winds were produced in tandem with a unique radar signature and surface observations of correlated wind and pressure perturbations along with steady or rising surface temperatures. The mechanism for the production of damaging surface winds in each case does not appear to be related to traditional methods related to surface-based convection but rather "up-down" trajectories that participate in the breaking of mesoscale gravity waves. During the presentation, the radar signature associated with gravity wave breaking within elevated convection will be introduced. Additionally, an early climatology and environmental discriminators between damaging and non-damaging events will be discussed. Finally, operational considerations and challenges will be explored in an effort to raise awareness that elevated convection can produce damaging surface winds, perhaps with a surprisingly high frequency.