Mesoscale Pressure Assimilation: A New Revolution for Research and Operations?

Surface pressure is a uniquely valuable observation. Pressure is one of the few surface variables that provides information about the deeper atmosphere. Pressure has less representational error than variables such as wind or temperature, and pressure biases are generally static and easily removed. The number of surface pressure observations has increased rapidly during the past few decades as the number of mesonets and internet-accessible observations has exploded across the U.S. Furthermore, many Android smartphones possess pressure sensors, with the pressure information made centrally available through several apps. This explosion of surface pressure data, coupled with ensemble-based data assimilation approaches (such as EnKF) has the potential to revolutionize mesoscale weather prediction. This presentation will review the current surface pressure observing assets and will demonstrate the impacts of high-density pressure observations for a variety of weather situations over the Pacific Northwest using a high-resolution (4-km) EnKF system.