Wind Data Examined 
At the time of this study, there was not a truly comprehensive 
meteorological station being operated in the harbors, so that data sources were 
sometimes difficult to access, or data were in a format that was difficult to 
handle (e.g., strip chart records). Wind data examined included those from 
the Headquarters buildings of the Port of Los Angeles (POLA) and the Port of 
Long Beach (POLB), the Los Angeles Pilot Station and the Los Angeles 
breakwater, the Los Angeles International Airport, and the Long Beach 
Airport, as shown in Figures 4 and 5. Data from the airports are 
comprehensive but may not be truly representative of the wind conditions over 
the harbors as Figure 6 shows, which compares data at the breakwater and the 
Long Beach Airport. Figure 7 compares monthly average wind conditions at 
the Los Angeles and Long Beach Airports, which indicates lower average 
winds at Long Beach Airport, 5 miles inland. The Los Angeles Airport is 
adjacent to the ocean, but differences in wind direction exist between this 
airport and the harbors. This is due to change in shoreline orientation and 
existence of hilly terrain just west of the harbors (as can be noted in 
Figure 4), which are important factors affecting the daily shoreward winds. 
Data gathered by WES on the San Pedro breakwater near Angel’s Gate 
from July 1984 to November 1988 are probably the most representative of 
winds directly over harbor waters. The monthly summary roses are included 
as Plates 1 - 26. Bar charts summarizing the data by months are included in 
Appendix A. These data do not cover the entire period from July 1984 to 
November 1988, due to occasional equipment problems and logistical 
problems associated with funding constraints; however, they appear to 
represent seasonal variations in patterns. The anemometer was 30 ft above 
water and sampled data every one-half hour. Wind conditions selected for 
model testing described in this report were obtained from this data set. 
An analysis was performed to examine strong winds and gustiness using 
strip chart records of wind speed and direction recorded at the Los Angeles 
Harbor Pilots’ Station (Figure 4). Data from 27 September 1976 through 
2 February 1983 were examined, and for maximum hourly gusts (where a 
gust is defined here as a rapid rise - a minute or less - in wind speed and a 
similar decline), the gust direction and the average hourly wind speed and 
direction were determined. A total of 438 events occurred, with most of the 
lower values reflecting afternoon onshore winds from the west and southwest. 
The higher wind speeds and gusts were from the east and southeast, associated 
with approaching fronts. The upper portion of Figure 8 shows maximum 
hourly gusts during high gust conditions (typically greater than 20 mph) 
versus average hourly wind speed. A linear relation between gust strength, 
G (in mph), as defined above, and average hourly wind speed, W (in mph), 
was determined to be 
G=1.1W+6.1 
This type of information, though not critical to effects on circulation in the 
harbors, may be important to ship handling and the roll motion of moored 
Chapter 2 Winds Over the Harbors 
