Destructive Factors

Tide

•In Abaco the high tide ranges from 3.5 - 4 feet and it occurs once a day.

The mean tide would be around 2 feet.

Storm Surge

Storm surge is simply water that is pushed toward the shore by the force of the winds swirling around the storm. The height of the surge is dependent on the characteristics of the storm, and the make-up of the shoreline and sea floor.

 

Surge Factors from Storm Characteristics

            -The more intense the storm (i.e. higher wind speeds), the higher the wave heights and storm surge.

            -The faster the storm moves, the quicker the surge piles up and the harder it strikes.

            -Generally, the more perpendicular the storm hits, the higher the surge will be. Also, bays and inlets increase the storm surge height.

Surge Factors from Shoreline and Sea Floor Characteristics

    -Bays, headlands and offshore islands can funnel and amplify the storm surge.

            -The surge builds up more strongly if the slope of the sea bed at the coast is shallow. If the sea bed slopes steeply, or if fringing reefs are present, then the surge will be less.

        

 

The Saffir-Simpson Scale for Hurricane Classification gives a general idea of storm surge based on the wind speeds and category of the hurricane:

Saffir-Simpson Scale for Hurricane Classification
Strength	Wind Speed (kt)	Wind Speed (mph)	Pressure (millibars)	Pressure (inches Hg)	Storm Surge (ft.)
Category 1	65-82 kt	74-95 mph	>980 mb	>28.94 in.	4-5 ft.
Category 2	83-95 kt	96-110 mph	965-979 mb	28.50-28.91 in.	6-8 ft.
Category 3	96-113 kt	111-130 mph	945-964 mb	27.91-28.47 in.	9-12 ft.
Category 4	114-135 kt	131-155 mph	920-944 mb	27.17-27.88 in.	13-18 ft.
Category 5	>135 kt	>155 mph	<919 mb	<27.16 in.	>18 ft.
Tropical Cyclone Classification
Tropical Depression		20-34 kt or 23-39 mph
Tropical Storm		35-64 kt or 40-73 mph
Hurricane		65+ kt or 74+ mph

 

Wave Heights

Wave heights during a hurricane can be very large as shown in the following diagrams. The heights and breaking points depend on the shoreline characteristics, but are devastating non e the less.