Surface Winds at Landfall of Hurricane Andrew (1992)—A Reply

We appreciate this opportunity to (i) clarify the simulation of surface winds at landfall of Hurricane Andrew (1992) as reported in Liu et al. (1997, hereafter referred to as LZY); (ii) make more detailed comparisons with one of the most sophisticated surface analyses of a landfallen hurricane by Powell and Houston (1996, hereafter referred to as PH96); and (iii) present the simulated winds at the surface and flight levels during the preand postlandfall periods. In LZY, we have shown that the model simulates the size of the eye reasonably well, the radius of maximum wind (RMW), and its asymmetry as well as the general distribution of surface winds with a peak magnitude greater than 65 m s21 near the northern RMW–coastline intersection (see their Fig. 7), as verified against PH96’s analysis. In addition, the model reproduces the rapid filling in central pressure and the rapid decrease in surface winds of the storm during Andrew’s landfall (see Fig. 2 in LZY). However, the model does not appear to produce the surface wind discontinuity across the coastline to the extent that was subjectively analyzed by PH96 (cf. Figs. 4b and 4c herein). It should be pointed out that the discontinuity in PH96, and other observational studies cited by Powell and Houston (1999, hereafter referred to as PH99), was not obtained from direct observations. We do not question the existence of pronounced changes in surface winds across the coastline, but we believe that their analyzed sharp discontinuity associated with intense normal-to-coastline flows and the absence of a transition zone downstream from the coastline are unrealistic and attributable to their ‘‘converting the flightlevel data using their boundary layer model over land