Evaluation of Planetary Boundary Layer Schemes in Hurricanes over Land through Comparison of Surface Winds in Observations and Simulations of Hurricane Wilma (2005)

Although considerable effort has been made toward improving how numerical models simulate the surface wind field in hurricanes over the ocean, relatively little attention has been given to hurricanes over land. This study uses the landfall of Hurricane Wilma (2005) to assess how well two widely-used boundary layer parameterizations – the Yonsei University (YSU) scheme and the Mellor-Yamada-Janjic (MYJ) scheme – can accurately capture the spatial and temporal evolution of the surface wind field over land. First, using the vortex bogussing technique of Rappin et al. (2013), WRF model simulations of Wilma are produced with tracks, landfall locations, intensities, and sizes of the wind field that are very close to observations. In contrast to the findings of some earlier studies, the storm structures and boundary layers produced by the two different parameterizations are quite similar while the storm is over water. Over land, the differences become greater, with the YSU scheme most notably exaggerating the effects of urban areas on near-surface wind speed. Both schemes reproduce time series of wind speeds at some locations remarkably well, but are less accurate in others, particularly the urban areas of Fort Lauderdale and West Palm Beach. The simulations reveal complex features in the surface wind, due both to mesoscale eddies and to local variations in surface roughness and land use.