Meteorology and Remote Sensing

Hurricanes and Tropical Storms in Florida Bay

Florida Bay Project Profile - 171

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Questions: What effect have major hurricanes had on water-levels, waves, currents, and sediment transport in Florida Bay? How might this information be incorporated into computer models designed to predict the effects of future tropical storms and hurricanes on Florida Bay ?

Background/Project: Tropical cyclones (hurricanes and tropical storms) are believed to exert considerable influence on the condition of Florida Bay. These cyclones affect the bay by adding decaying organic material to the surrounding environment from mangrove trees and seagrasses damaged by the wind and storm surge. Wind fields from cyclones generate surface stress which affects bay circulation patterns and sediment transport. Because the "multiple pond and bank" nature of Florida Bay inhibits sediment transport, hurricanes are believed to play a critical role in flushing the bay or transporting sediment within the bay environment.

To predict the response of Florida Bay to episodic wind events, wind fields of past cyclone events have been reconstructed. Grids of tropical cyclone surfacewind fields are being generated from real case analyses and numerical model simulations are being created to produce a catalog of datasets.

Findings To Date: Hurricane wind fields are available on the Storm Atlas on the Hurricane Research Division World Wide Web site  http://www.aoml.noaa.gov/hrd .

Wind fields can be used by scientists to estimate the potential impacts of future tropical cyclones on the south Florida ecosystem and especially on Florida Bay. The hurricanes used in this study were the Labor Day Hurricane (1935), Donna (1960), Betsy (1965), Felix (1987), Andrew (1992), Georges (1998), and Mitch (1998).

These tropical cyclones represent the vastly different scenarios for what might be expected over the southern extreme of the Florida mainland. The 1935 Labor Day Hurricane was the most intense hurricane known to have struck the USA. The wind field of this Category 5 hurricane was relatively small and concentrated when it crossed the Florida Keys and Florida Bay. Hurricane Donna (1960), a Category 4 hurricane , crossed the keys and bay on a similar track to 1935, but had a much broader wind field. Hurricane Andrew (1992) was a fast moving Category 4 when it struck the mainland. Andrew’s strongest winds were north of Florida Bay in the Everglades, but large amounts of vegetation were destroyed along the Florida Bay coastline. This decaying plant matter later caused water quality problems due to decomposing organic material. Recently, Hurricane Georges crossed the lower Florida Keys in September 1998 with peak sustained winds of 44 m/s (98 mph) over the southern portions of Florida Bay. Later, the remains of powerful Hurricane Mitch regenerated into a tropical storm in early November 1998 and crossed southern Florida. Mitch’s sustained winds ranged 15-25 m/s (33-56 mph) over Florida Bay as the storm moved rapidly across the state.

Status: Ongoing.

Restoration Impacts: Using observations from past tropical cyclone events, this project has produced wind field data. Scientists use these data to better predict the effects of future tropical cyclones on the bay and understand the ways in which hurricanes and tropical storms affect bay circulation and sediment transport patterns.

Funding Source: NOAA/Hurricane Research Division

Related Profiles: • FBPP 155 • FBPP 156