A Combined Wave and Surge Hindcast for the Coast of Florida During Hurricane Andrew

Tracy, B; Brandon, W

Wave hindcasting procedure and resulting wave conditions during Hurricane Andrew (August 22–24, 1992) are determined at one nautical mile (nm) (1.85 km) intervals from latitude 25.23 to 26.27°N along the Florida coast. Miami Beach, the site of a major hurricane shore protection beach fill project, is located in the center of this area. A planetary boundary layer hurricane wind model is used to calculate windfields which are compared to the National Data Buoy Center (NDBC) anemometer record at Fowey Rocks C-MAN station (latitude 25° 35'25"N, longitude 80° 5'48"W), located about 11 nm (20 km) east of the shoreline. Maximum hindcast wind speeds at 92082408 (YYMMDDHH) UTC (Co-ordinated Universal Time) are 48 mps (meters per second) compared with 51 mps measured at Fowey Rocks. The area around Biscayne Bay and Miami Beach is very shallow; therefore, surge levels are added to the wave hindcast input depths. The surge water levels are modeled using an explicit finite difference surge model that uses winds and barometric pressure as the primary forcing mechanisms. The Wave Information Study (WIS) wave model, a second generation spectral model, is used to calculate wave conditions using hourly windfields and surge to update the bathmetry. Maximum hindcast surge levels are +4.0 m MSL at an offshore station (2.0 m depth) and 1.85 km from shore compared to the closest maximum onshore measurement of +4.9 m. Maximum hindcast wave heights in Biscayne Bay are 4.0 m with a 6.8 m maximum in deeper water (8–9 m) adjacent the Miami Beach area. The shallow water adjacent to Miami Beach and Biscayne Bay limits the wave heights produced by this storm and reduces potential damage to the beach fill area.

A Combined Wave and Surge Hindcast for the Coast of Florida During Hurricane Andrew

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