Surface meteorological conditions during the Winter 1990 Navajo Generating Station Visibility Impairment Study

Surface weather conditions are measured during the Winter 1990 Navajo Generating Station Visibility Impairment Contribution Study (NGS Visibility Study for brevity) by means of a special-purpose set of weather stations on short towers. The data from these stations document conditions in the surface layer of air and offer an opportunity for studies both of wind flows in complex terrain and of the temperature, relative humidity and solar radiation conditions in the Colorado Plateaus region of northern Arizona and southern Utah. This paper describes the location and setting of the weather stations, the sensors and their exposure, the data acquisition methods, and the resulting data sets. The 70 kPa geopotential heights and wind speeds that are routinely measured by the Winslow upper-air observing stations are used to describe the overall nature of the 1990 winter season, to chart the passage of major upper-air features and to stratify the surface transport winds. Hodograms are presented which show the diurnal influence of nearby slope, wall and channel topography on local winds. 11 refs., 11 figs., 4 tabs.