This report describes the surface wind speeds during the passage of Hurricane Marilyn through the U.S. Virgin Islands on 15-16 September 1995. Sources of wind speed measurements during this period are described, along with procedures used to adjust these measured speeds to standard conditions, defined for the purposes of this report as the sustained speed (1-minute average) at 10 m above open water. These adjusted speeds provide a basis for the validation of surface wind speeds derived by the surface wind analysis system of NOAA's Hurricane Research Division. It is concluded that the maximum over-water sustained speeds in Hurricane Marilyn were approximately 40 m/s at St. Croix, 46 m/s at St. Thomas, 43 m/s at Culebra, and 26 m/s along the east coast of Puerto Rico. It is probable that locally higher speeds occurred in some over-land locations where topographic features such as hills, ridges or escarpments caused speed-up effects near the ground. In terms of the extreme wind climate for this region of the Caribbean, the maximum over-water sustained speeds at St. Thomas correspond to a mean recurrence interval of about 30 years, or an annual probability of 0.033 of being equalled or exceeded. In view of the fact that traditional practice is to design ordinary buildings and other structures to perform adequately with a comfortable margin of safety when subjected to a 50-year event (about 50 m/s in this case), the resulting wind damage in the affected area must be attributed to poor builidng practices and inadequate code enforcement rather than to excessively high winds.
Citation: NIST Interagency/Internal Report (NISTIR) - 5987
NIST Pub Series: NIST Interagency/Internal Report (NISTIR)
Pub Type: NIST Pubs
hurricanes, weather effects, wind velocity, building technology, codes, standards, natural disasters, structural engineering, wind damage, wind engineering, wind loads