Weather service concerned that wind farm could interfere with local forecasts 

“The National Weather Service uses that radar to issue any type of hazardous weather watches or warnings in (the Fort Drum) area,” she said, adding that the Federal Aviation Administration and the U.S. Air Force also use the Montague radar station.

Radar scans weather by emitting an energy beam and rotating 360 degrees at different elevation angles from 0.5 degrees to 19.5 degrees from the horizon.

Ms. Schultz said the beam would bounce off of the turbines at the lowest elevation angles, which she said are important for detecting lake effect snow, heavy rain, hail, damaging winds and tornadoes. Turbines would then appear on radar images depicting perception and wind velocity in the area, which Ms. Schultz said could cause “erroneous overestimates” in rain or snowfall measurements and make it difficult for forecasters to determine wind velocity.

“The lowest elevation angles are the most important for detecting hazardous weather,” she said. “For any wind proposals, we look at what impacts there would be for those lowest angles.”

Wind turbines are among a few examples of “clutter” Ms. Schultz said could inhibit weather data collection.

Buildings and other man-made stationary objects also contaminate data collection from radar, Ms. Schultz said, but the National Weather Service uses computer processing to filter those objects from radar images.

What separates wind farms from other stationary objects are their scope and the height and rotating blades of the turbines, which make them difficult to remove from radar images. Atlantic Wind plans to install up to 125 turbines for the 350 megawatt project, but the developer has not determined the height of its turbines.

Ms. Schultz said the National Weather Service has “no way to filter turbines out of the velocity data” or the precipitation data.

The National Weather Service is also concerned that the proposed Deer River and Roaring Brook wind farms in Lewis County, which are also owned by Avangrid Renewables, would have the same impact on the Montague radar, Ms. Schultz said.

The station is about two miles from Deer River Wind Farm’s southern project border in Montague and fewer than three miles away from Roaring Brook Wind Farm’s western border between Montague and the town of Martinsburg.

“We have had discussions with the developer and it has been a good dialogue,” Ms. Schultz said. “We try to work with developers and have a dialogue with them about how we can best align the turbines to reduce the impact.”

Officials from the Department of Defense did not return several requests for comment on Mad River Wind Farm’s potential impacts on Fort Drum.

The potential issues of encroachment at Fort Drum by wind turbines is one of 25 pieces of a land use study being undertaken by the Development Authority of the North Country.

Last May, the post’s Public Affairs Office said that the study would help find ways “for the coexistence of our training and future wind turbine development in the north country.” The post’s Wheeler-Sack Army Airfield serves a wide range of rotary and fixed-wing aircraft, and the Public Affairs Office said turbines may affect its air traffic control services.

Tom Flanigan, spokesman for Elise M. Stefanik, R-Willsboro, said she is a supporter of renewable energy but is also concerned with the military’s readiness and training capabilities at installations, including Fort Drum.

“She will continue to work with wind turbine companies in the district and maintain discussions with Fort Drum leadership to ensure effective uses and relationships of both entities and is soliciting feedback on that legislation from stakeholders,” Mr. Flanigan said.