EM 1110-2-1100 (Part II)
(Change 1) 31 July 2003
Figure II-2-1. Ratio of wind speed of any duration Ut to the 1-hr wind speed U3600
EXAMPLE PROBLEM II-2-1
1-hr average winds for wave prediction
10-, 50-, and 100-year values of observed winds at a buoy located in the center of a large lake (U10
= 20.3 m/s, U50 = 24.8 m/s, U100 = 28.2 m/s). It is also known that the averaging interval for the buoy
winds is 5 min.
Using Figure II-2-1, the ratio of the fastest 5-min wind speed to the average 1-hr wind speed is
approximately 1.09. Using this as a constant conversion factor, the 10-, 50-, and 100-year, 1-hr wind
speeds are estimated as U'10=18.6 m/s, U'50=22.8 m/s, and U'100=25.9 m/s.
Meteorology and Wave Climate