Atmospheric Radar Research Center

A GIS system will be used to map:

• The 0.5° coverage patterns for the WSR-88D radars in the study region and may also include the next two higher elevation angles, depending on the topography of the particular sites.
• Locations of installed wind farms and those presently under construction. This portion of the effort will lead to a data base containing latitude, longitude, and elevation of every wind turbine in the study region, along with the engineering characteristics of machine (nacelle height, rotor diameter, range of rotation rate, etc.). In reality, we may be restricted to information on some wind farms as a whole.
• Locations where wind farms are likely to be built in the future, based on availability of the wind resource, access to the electrical grid for distribution purposes, etc.

The National Weather Service offices in the study region will then be surveyed (via the Radar Operations Center) to obtain first-hand accounts of the observations of WTC by forecasters and radar technicians. These accounts will then be compared with the mappings to determine relationships between the WTC and the point(s) of origin. This portion of the study will determine how often WTC is seen, at what ranges, and its observed characteristics. We will also ask about locally devised mitigation procedures for this problem.

The survey instrument will be constructed to not only determine what is being observed (generators with rotating blades and/or low-speed wake), but also the conditions in which WTC occurs (time of day, wind direction, atmospheric stability). Follow-up telephone conversations will likely be necessary with survey respondents. It is expected that most of the effort on this topic will be on situations where the radar senses the plume of low-speed air downstream of a wind farm. This portion of the study will determine when WTC can be expected, in terms of the regional meteorology, and may provide clues for strategies for coping with its occurrence.