Abstract

SYNOPSIS

A brief summary of what is known bearing directly on this subject concerning wind and waves is given.

Hurricanes are in all instances preceded by storm tides. The water commences rising on the coast in front of the cyclonic area, one to two days before the storm in experienced.

The wind velocities and directions in different parts of the hurricane, as deduced theoretically, do not meet the requirements in this study to explain the rises in tides. Composite charts showing the actual wind directions and velocities determined from stations in the different parts of the cyclonic area are submitted. In the right-hand rear quadrant the winds blow with much greater velocity and persist in the same direction longer than in any other part of the hurricane. At stations in this quadrant the wind has been found to blow for 24 hours or longer with a direction in line with the advance of the hurricane, with an average velocity of 60 miles per hour, and for 13 hours at 70 to 85 miles per hour. In other parts of the cyclonic area the wind continues to blow over the water in the same direction for only a few hours.

Winds in the cyclonic area over water develop waves of a size and length which bear a relation to the sustained velocity of the wind and the length of time the waves are under the influence of the same wind direction. Waves of different sizes are developed in proportion to the winds which prevail in the different parts of the cyclonic area. The largest and longest waves are created in the rear right-hand quadrant; these waves pass on through the cyclonic area and move to shore where they cause a rise in the water in the front of and on the right of the line over which the center of the hurricane is advancing. This rise begins when the center of the hurricane is 300 to 500 miles distant, and continues until the hurricane moves inland. The heights of the water reached at shore near the center of the storm vary from S to 15 feet above mean Gulf level.

Changes in the position of the rise of the storm tide indicate changes in the course of the storm.

Bold-face figures in parenthesis refer to authorities preceded by the same figure in the bibliography at the end of this paper.

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