The recent push to "go green" and utilize some of the Earth's natural resources as a means of clean, renewable energy has had an unexpected side effect. Across the country, a growing number of doppler radar sites are experiencing interference caused by large wind energy turbines...many of which extend several hundred feet above the ground and into the radar's direct line of sight. The result, at the very least, has been an increase in "ground clutter" during stable weather patterns...but the rotating turbines can also trigger false severe weather signatures. There has already been at least one documented case of such an occurrence.
Conventional doppler radar is equipped with a sophisticated clutter/interference removal scheme, however the scheme was designed to filter out spurious returned (reflected) energy that has little or no motion. This is effective for removing the returned signals from terrain, buildings, and other non-moving structures. Unfortunately, the radar sees the rotating wind turbine blades as targets having reflectivity and motion, hence processes these returns as weather. In a particular case near the Dodge City, Kansas doppler radar site a false "tornado vortex signature" (TVS) was triggered! Many meteorologists fear that the masking or misrepresentation of certain thunderstorm characteristics could potentially reduce warning effectiveness in the vicinity of the wind farm.
In light of the incident in Dodge City, Kansas...the National Weather Service is actively working with various wind energy corporations throughout the country to ensure the proper placement of wind farms that may be constructed in the future. Several wind farms have already been constructed in Steuben County and more are currently in the planning stages elsewhere throughout our viewing area...so this is an issue that will ultimately have to be addressed here in the Twin Tiers, as well.