5 . Storm Associated Changes 



Another aspect of this study was an attempt to document the abrupt 

 changes in beach profile configuration caused by storms and periods of 

 high waves. Documentation of these changes was made by profile measure- 

 ments before and after the occurrence of storms or high waves. However, 

 the problem in this plan was in predicting the occurrence of storms in 

 order to efficiently make "before surveys." The only information avail- 

 able for storm prediction was U. S. Weather Service forecasts for the 

 Pacific coast which were thought to be reliable since most of the local 

 winter storms progress southward along the coast and can be identified 

 before arriving in the study area. However, it was soon realized that 

 it is difficult to predict the occurrence of these storms and to make 

 a representative "before" survey . 



During the winter of 1972-73 the first winter storm occurred over 

 the weekend of 18-19 November 72 so that a survey previous to the event 

 was not made, but a survey was made immediately following the storm. 

 This storm caused extensive changes in the beach and essentially altered 

 the profile to a winter configuration. This change in profile configur- 

 ation was described as part of the seasonal changes between November 1972 

 to April 1973, and is shown in Figure 7. Several storms and periods of 

 high waves occurred during the 1972-73 winter season following the 

 November storm. Most significant of these were the following: 



(a) 9-10 January 1973 9-foot-high breakers 

 17 January 1973 Beach profile survey 



(b) 12-15 February 1973 Storm 7- to 10-foot-high breakers 

 16 February 1973 Beach profile survey 



(c) 12-14 March 1973 Storm 7- to 10-foot-high breakers 

 16 March 1973 Beach profile survey 



Comparisons of the beach profiles made from month to month following 

 these storms and high wave occurrences indicate that each subsequent 

 event had less effect in modifying the profile configuration than the 

 first storm in November 1972. 



During the winter season of 1973-74 storm predictions were again 

 based upon U. S. Weather Service forecasts in an attempt to document the 

 changes due to storms with profile surveys. However, the 1973-74 winter 

 season was relatively mild with few storms and occasional occurrences of 

 high waves. The significant surveys and occurrences of high waves dur- 

 ing this season were as follows: 



