During both field experiments, a real-time forecast was performed at the University of Utah with a mesoscale community Weather Research and Forecasting (WRF) model at high resolution (~1 km horizontally), four times (at 00, 06, 18, and 24 UTC) a day. The purpose of this real-time forecasting was not only to support decision-making during the field program but also to provide a useful database to evaluate the WRF model's performance in predicting synoptic flows over mountainous terrain. During the field program, a series of 48-h forecasts were produced for over 200 forecast leading times and for all Intensive Observational Periods (IOPs) during SeptemberOctober 2012 and May 2013. After the field experiments, these forecast results were compared with observations collected from the field experiments.
Preliminary comparison between the WRF forecasts and observations show notable biases, with diurnal variations in near-surface atmospheric conditions under quiescent cases and flow-dependent patterns in errors associated with transitions and strong synoptic forcing cases. More comparisons are in progress with available soil states, surface flux, and profile observations from multiple platforms. The ability of the WRF model to predict synoptic and local flows over complex terrain, error characteristics and sources, and deficiencies in model physical parameterizations will be diagnosed and commented on. Additional numerical experiments and data assimilation will also be suggested. Detailed results will be presented during the conference.