From UBC 97, under SECTION 1616 – DEFINITIONS:BASIC WIND SPEED is the
fastest-mile wind speed associated with an annual probability of 0.02 measured
at a point 33 feet (10 000 mm) above the ground for an area having
exposure category C.From SBC 301, under SECTION 6.2 – DEFINITIONS

Basic Wind Speed, V. 3-second gust speed at 10 m above the ground in Exposure C
(see Section 6.4.2) as determined in accordance with Section 6.4.1.

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FIGURE 6.4-1
BASIC 3-SECOND GUST WIND SPEED IN km/h FOR SELECTED CITIES OF SAUDI ARABIA.
ADOPTED FROM SAUDI ARAMCO DATA SAES A-112.From [ 2007 California Building Code‚
Title 24‚ Part 2 (First Printing)‚ Includes Supplements through Jan 11 ]
–  SECTION 1609 WIND LOADS  – 1609.3 Basic wind speed.**1609.3.1 Wind speed
conversion.**When required, the 3-second gust basic wind speeds of Figure 1609
shall be converted to fastest-mile wind speeds, Vfm, using Table 1609.3.1 or
Equation 16-34.
(
Equation 16-34)where: V3S = 3-second gust basic wind speed from Figure 1609.
TABLE 1609.3.1 EQUIVALENT BASIC WIND SPEEDS a, b, c

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For SI: 1 mile per hour = 0.44 m/s.

a. Linear interpolation is permitted.
b. V 3S is the 3-second gust wind speed (mph).
c. Vfm is the fastest mile wind speed (mph).