OBSERVED AND MODELED WIND AND WATER-LEVEL RESPONSE FROM TROPICAL STORM MARCO (1990)

The Hurricane Research Division (HRD) analyzes surface wind fields in tropical storms and hurricanes using surface wind observations and air craft flight-level wind measurements in the vicinity of the storms. Th e analyzed surface wind fields for Tropical Storm Marco (1990) were co mpared with the wind fields used for input in the National Weather Ser vice's Sea, Lake, and Overland Surge from Hurricanes (SLOSH) model. Th e HRD wind fields were also used to determine the wind speeds and dire ctions corresponding to the storm surge at tide gauges along Florida's west coast. The observed storm surge at the gauges was compared with the storm surge computed by the SLOSH model. Time series of the SLOSH model winds were compared with time series based on the analyzed wind field at each tide gauge, because in most cases there were no wind obs ervations available at these gauges. The comparisons of the analyzed a nd modeled winds and the observed and modeled storm surge show that th e SLOSH model reasonably represented the extreme storm tide effects on two basins with relatively complicated coastlines. However, SLOSH ove restimated surface winds in areas of offshore flow, resulting in predi ctions of excessive negative surge. It is suggested that real-time sto rm surge model calculations, based on input from real-time surface win d analyses, have potential for the support of emergency management res ponse and infrastructure recovery efforts during and immediately follo wing landfall.