Impacts of UAS Data on Thunderstorm Forecasts during PRECIP

Unmanned aircraft can collect observations in areas not readily sampled by other platforms, such as the ability to conduct low-altitude transects across structures like fronts. However, the utility of these observations to improve model forecasts of thunderstorms and storm environments has not yet been determined. The 2016 field campaign for PRECIP includes an unmanned aircraft, with the specific goal of collecting data near and across air mass boundaries. Data denial experiments are being conducted to measure the value of assimilating low-level aircraft observations to nowcasting thunderstorm activity. These experiments will include denial of UAS, mobile mesonet, VAD wind profile, radiosonde, and AMDAR data to evaluate the relative impacts of each platform. These observing system experiments are being conducted in a 1 km nest using HRRR initial and lateral boundary conditions, with verification focused on thunderstorm coverage, location, and strength.  Aircraft and surface data were collected in the Nebraska Panhandle on the afternoon of 28 June 2016, prior to initiation of thunderstorms over southeast Wyoming and before an intense overnight MCS. Although no air mass boundary was present in the area, a north-south and an east-west flight of approximately 60 km were conducted. The impacts of data from each flight will be examined separately. Additional intensive observing periods are planned later in the summer and fall as conditions permit. Results from the data denial experiments for all 2016 PRECIP deployments will be presented.