Hurricane Marilyn in the Caribbean: Measured Wind Speeds and Design Wind Speeds Compared.
Hurricane Marilyn in the Caribbean: Measured Wind
Speeds and Design Wind Speeds Compared.
Marshall, R. D.; Schroeder, J. L.
NISTIR 5987; 52 p. March 1997.
Available from: National Technical Information Service
Order number: PB97-158166
hurricanes; weather effects; wind velocity; building
technology; codes; standards; natural disasters;
structural engineering; wind damage; wind engineering;
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.