96 



FISHERY BULLETIN OF THE FISH AND WILDLIFE SERVICE 



manuals. It does not mean that the manuals are 

 in error but rather means that a non-periodic, 

 usually short-term wind effect must be super- 

 imposed upon the published predictions. One of 

 the most challenging problems facing the meteor- 

 ologist-oceanographer is that of finding a way to 

 calculate these wind effects for different situations. 

 Some work has been done by Dietrich (1937). 



HURRICANES 



The Galveston flood tide of 1900 in which 

 6,000 persons lost their lives emphasizes the impact 

 of the Gulf coast hurricane upon that region. 

 Much has been written on this and similar storms. 

 Some references are the Coast Pilot, Tannehill 

 (1944), Cline (1926, 1933), Riehl and Burgner 

 (1950), and Shisler (1949). 



Nearly 80 percent of the hurricanes appearing 

 in the Gulf form outside and enter moving north- 

 westward across the Yucatan Channel and Florida 

 Peninsula area. Approximately 15 percent form 

 in the northern Gulf, and most of the remainder 

 form in the southwestern Gulf. They travel at 

 an average speed of 10 to 13 knots. The most 

 common path is westward becoming northwest- 

 ward and northeastward. Some, however, do 

 not turn northward. The months of greatest 

 frequency and intensity are August, September, 

 and October. There are an average of about nine 

 hurricanes each year in the western North Atlantic, 

 and many of these enter the Gulf. 



Hurricanes are usually 100 to 500 miles in 

 diameter. In the eye of the storm is a region of 

 calm where the water level rises in a "hurricane 

 wave" which may be 20 feet or more in height. 

 Around the storm center, high-wind waves 

 develop. Passing out of the wind area these 

 waves become swells and often provide the first 

 indication that a hurricane is approaching. 



Much of the damage caused by hurricanes in 

 coastal areas is due to the fact that the wind- 

 driven storm tide raises the water level sufficiently 

 that the high breaking wind waves are carried 

 across breakwaters and retaining walls into un- 

 protected inshore areas. The tracks of the centers 

 of hurricanes which caused the highest tides of 

 record on the Gulf coast are shown in figure 22. 

 A detailed discussion of such meteorological tides 

 is given by Cline (1933). 



In recent years much has been learned about 

 the formation and motion of hurricanes from the 

 weather flights into the centers of the storms 

 made by the United States Navy and other 

 flights made by the Air Force. In addition, the 

 storms have been followed by radar sets, since 

 they make a distinctive pattern on the radar 

 screen. 



APPLICATIONS OF MARINE 

 METEOROLOGY IN THE GULF 



The heavy investments by the petroleum in- 

 dustry in the shallow waters of the Gulf (some 

 250 million dollars) are greatly affected by mete- 

 orological conditions as evidenced, for example, 

 by a symposium on this and related subjects 

 appearing in the February 23, 1950, issue of the 

 OU and Gas Journal. Glenn (1950) discusses the 

 place of meteorologists in improving the safety 

 and efficiency of offshore petroleum operations. 



The many large industrial organizations on the 

 coast need information about offshore weather 

 for use in conducting their operations. Several 

 organizations have established weather observa- 

 tion stations including radar facilities, such as 

 those described by Jorgensen and Gerdes (1951). 



Fishing here, as elsewhere, is successful or not 

 depending to a large extent upon the weather. 

 Navigation, protection of beaches, construction 

 along the coast, and recreation all furnish applica- 

 tions for knowledge gained in the study of marine 

 meteorology. 



FURTHER SOURCES OF INFORMATION 



Many pertinent articles on marine meteorology 

 are reproduced on the back of the Pilot Charts. 

 An index to those between January 1946 and 

 September 1950, inclusive, appears on the chart 

 for November 1951. Some examples are: Cyclonic 

 storms — October 1949, Fog — September 1946, 

 Hurricanes and Tropical Disturbances — August 

 1946, 47, and 48, Northers— September 1949, 50, 

 and 51, Line Squalls — March 1948, Northers —  

 September 1947 and November 1948, Water- 

 spouts — December 1948, and the Gulf Stream — 

 August 1950. These charts may be obtained for 

 30 cents each by addressing a request to the 

 United States Navy Hydrographic Office, Wash- 

 ington 25, D. C. 



