MAXIMUM DAILY WIND GUSTS RELATED TO MEAN DAILY WIND SPEED. TECHNICAL NOTE

The National Weather Service routinely records meteorological data, including winds, at most large airports around the United States. These data directly support airport operations but also help establish regional historical information on the wind climate. Wind data are of interest to civil engineers for various reasons. Wind loads on structures are determined both by sustained winds and by the gusts contained within them. This analysis presents a method to predict the expected value of the daily maximum wind gust speeds and their statistical distribution given the mean daily wind speed. A gust factor, G, is proposed, defined as (ug/U)-1, where ug=gust speed, and U=mean daily wind speed. A relationship between G and U has the form G=A x (U to the nth power), and the data are lognormally distributed about the G versus U regression line. Data from six weather stations--Atlantic City, New Jersey; Philadelphia, Pennsylvania; Wichita, Kansas; Los Angeles and San Francisco, California; and Champaign/Urbana, Illinois--are analyzed and found to fit the proposed model.