Overall, the island blocking, orographic lifting, and the diurnal cycles of the surface winds, temperature and rainfall over the Island of Hawaii are well simulated. The simulated splitting airflow, strong winds over the northern and southern tips, Waimea Saddle, and Humu’ulu Saddle of the island of Hawaii are in good agreement with observations. At most areas on the windward side and the Kona coast on the leeside, the upslope (downslope) flow duration and the morning (evening) transition time from downslope (upslope) flow to upslope (downslope) agree well with observations. The diurnal rainfall maxima were well simulated with a maximum in the afternoon hours on the windward slopes and the leeside slopes, and a nighttime maximum over the windward coastal areas.
Some discrepancies exist between the model simulations and the observations. The simulated daytime upslope flow is 1 – 2 m s-1 smaller than observations. The simulated rainfall accumulation during HaRP is 10 - 50% smaller than the observations with larger relative errors on the leeside areas and the windward slopes. The simulated surface temperature during HaRP is ~ 0.5º - 2.5º C lower than observations on most areas of the island except on some areas of the windward lower slopes, where the simulated surface temperature is ~ 0.5º higher. Factors attributed to the simulation errors will be discussed.
Supplementary URL: http://www.soest.hawaii.edu/MET/Faculty/mm5