Precipitation Forecasts for COAMPS-Hydro - An Initial Look from Hurricane Irene (2011)

Hurricane Irene (2011) caused widespread severe flooding and power failures over three major catchment watersheds – Tar-Pamlico-Neuse in North Carolina, Susquehanna in Pennsylvania, and Chesapeake Bay in Virginia. In an effort to evaluate the development of COAMPS-Hydro, sensitivities of the precipitation forecast are investigated using the high-resolution Coupled Ocean/Atmosphere Mesoscale Prediction System (COAMPS) that is fully coupled with the NOAH land surface model (LSM) and NAVY Costal Ocean Model (NCOM). In this study, we examine the variation of model simulated precipitation forecasts arising from different LSM initializations such as the NASA Land Information System (LIS) and from different microphysics sedimentation schemes coupled with two-moment prediction. Precipitation differences using COAMPS bulk microphysics and the more advanced two-moment microphysics will be discussed in terms of how the pre-landfall aerosol environment is modified by the advancing storm system. Other model parameters such as temperature, moisture, and wind will be evaluated as well.