High resolution Unified Model simulations of T-REX IOP-6, comparison with observations

Probably the most dramatic wave/rotor event during the recent T-REX field campaign in the Sierra Nevada mountains, USA, occurred during IOP-6. Observations indicate regions/periods of intense near-surface flow and turbulence and strong spatial and temporal variability, making this event a challenge for forecasting models. High resolution (333 m) nested simulations of the IOP using the Met Office Unified Model (UM) have been performed, and indicate a highly structured flow aloft and near the surface, including downslope/gap winds and periodic/propagating features. A combination of dense near-surface instrumentation, observations of the wave field aloft and three-dimensional remote sensing are used to investigate the extent to which the simulated flow structure is representative of the real flow.