HURRICANES GENTRY AND SIMPSON 323 



people, according to estimates appearing in the press. During the 

 1955 season the floods caused in Mexico by hurricanes Hilda and Janet 

 and tropical storm Gladys are reputed to have inflicted upon Tampico, 

 Mexico, its greatest natural disaster. 



To many people, rainfall is the most sensational result of a hurri- 

 cane. Rainfall accompanying hurricanes and tropical cyclones is 

 nearly always heavy and frequently torrential. At Baguio in the 

 Philippines, in July 1911, 46 inches of rain fell in 24 hours during the 

 passage of one tropical storm. In the United States the heaviest rain- 

 fall during such a storm was 39.7 inches, which fell during one 48-hour 

 period at Thrall, Tex., during the storm of September 8-10, 1921. 



The quantity of rain that can fall from one slow-moving tropical 

 storm almost staggers the imagination. In hurricane Diane of 1955, 

 over 16 billion tons of rain fell, according to rainfall estimates pre- 

 pared by Schoner and Molansky [19], who also estimated that over 

 30 billion tons of rain fell during the passage of hurricane Connie. 

 Thus, approximately 46 billion tons of rain fell during the two 

 storms. 



Many of the heaviest recorded rainfalls have been in storms of 

 less than hurricane intensity. Even in storms that were hurricanes 

 at one time, the heaviest rainfall frequently occurs after the winds 

 are no longer of hurricane intensity. This was the case with hurricane 

 Diane of 1955. Although at one time while it was still at sea the 

 highest winds in Diane were 125 m.p.h., the maximum measured 

 winds along the shore when Diane moved inland were 74 m.p.h. in 

 gusts at Wilmington, N. C. As Diane moved farther inland the 

 winds further decreased, and as the gales subsided, so did the public's 

 concern with the storm. Diane moved northward across North 

 Carolina and Virginia and into Pennsylvania before turning eastward 

 for the coast — then came the deluge ! The torrential rains from Diane 

 fell on grounds still saturated from the rains of Connie. From the 

 Poconos of Pennsylvania to southeastern New England rain in excess 

 of 8 inches was reported at many places. The greatest amount — over 

 19 inches — fell in the highlands northwest of Hartford, Conn. All 

 this rain fell long after Diane had ceased to have winds of hurricane 

 force [24]. 



Rainfall around a tropical storm is usually distributed asymmetri- 

 cally. This is particularly true when a hurricane is moving. Accord- 

 ing to Dr. I. M. Cline [2] , very little rainfall occurs in the rear half 

 of storms moving inland on the Gulf or south Atlantic coast of eastern 

 United States. The heaviest rainfall usually occurs in the right front 

 quadrant of the tropical storm, according to Cline. There are excep- 

 tions, of course. As a hurricane moves inland, heaviest rainfall fre- 

 quently occurs far in advance of the storm. This is particularly true 



