Vector Wind Velocity, Speed, and Mode Summaries for the Southeastern U. S.

Abstract

This report presents wind speed and direction summaries for a wide area of the Southeastern United States (including EPA Region 4) and portions of the Ohio and Mississippi River Valleys in a monthly time series format that is further broken down for eight hours of the day (01:00, 04:00, 07:00, 10:00, 13:00, 16:00, 19:00, 22:00 EST). The data used for these summaries were obtained from the International Station MeteorologicalClimate Summary (FCCA, 1996), a publicly available source of tabular data from weather stations around the world distributed through the National Climatic Data Center. The advantage of examining the data in the form presented in this report is that it is far easier to examine and understand regional and diurnal weather patterns than would be possible with the tabular data in its original format. The winds presented here can be viewed online in any of three formats through an Internet link. The first format is the traditional wind rose as used in our earlier reports f or 13 stations in the Southeast, c.f., Weber, Buckley, and Parker 2002 and Weber, Buckley, and Kurzeja 2003. The second format is the mode, or most frequent wind direction sector from the wind rose plots (i.e., the longest ''petal'' from the individual station roses). Finally, the third format depicted is the average wind vector. The average wind vector was determined by extracting the wind speed and direction for each of the 16 sectors from a station's wind record and then summing components of these vectors for the month and time of observation. Each station was then plotted on a sequence of maps for the Southeastern U.S. using ArcView software. These maps form a time series in 3-hour increments showing changes in vector wind speed and direction for each month of the year. The complete set of color figures are too numerous to be included in this report, but may be accessed by contacting one of the authors.