In recent years, there has been dramatic growth in the use of wind turbine “farms” to generate electricity and so diversify our Nation's energy sources. Continued growth in the number and size of such wind farms is expected. These wind farms can have over 100 towers, with turbine blade tip heights exceeding 400 feet above ground level.

Experience has demonstrated that when wind farms are located in the radar line-of-sight of Weather Surveillance Radar-1988, Doppler (WSR-88D, also known as NEXRAD) systems, interference (spurious radar echoes) from the towers and turbine blades can impact radar data quality and the performance of product-generation algorithms. Many wind farms now in operation were installed without apparent knowledge of their possible impacts on nearby (< 100km) weather radars. During the last year the WSR-88D Radar Operations Center (ROC), on behalf of the Next Generation Weather Radar (NEXRAD Program), has been working with other federal agencies to adopt a policy that addresses impacts of wind farms on weather surveillance radars while encouraging wind farm development at locations where radars and wind farms can co-exist with minimal interference. The ROC has begun an outreach program to inform wind farm developers early in their planning process of the impacts wind farms can have on WSR-88Ds. This effort has resulted in instances of developers moving wind turbines in order to reduce their impact of WSR-88Ds.

This paper and presentation will provide examples of the impact of wind farms on WSR-88Ds; outline ROC efforts since the last AMS Annual Meeting presentation of engaging wind farm developers; and report the status of federal policy regarding the siting of wind farms.