By TIM ALEXANDER

Illinois Correspondent

WASHINGTON, Ill. — Despite industry promises to address the problem, wind farms in central Illinois and elsewhere continue to play havoc with Doppler radar images on mobile weather apps, meteorologists say.

The issue, first brought to light by the National Weather Service in 2009, was recently revisited by NWS coordination meteorologist Chris Miller, who told the Bloomington Pantagraph newspaper in January that the massive turbines used in area wind farms can generate enough wind and other types of interference to influence readings, depending on atmospheric conditions.

Miller, who works in Lincoln, said the weather service’s radar picks up on wind farms in Logan, Macon, and McLean counties in central Illinois. Though modern Doppler radar such as what is used by the NWS contains features that can compensate for some of the interference, radar sent online or through phone apps may not include the same filters.

This was confirmed by Mike McClellan, a meteorologist with the Mobile Weather Team in Washington, Ill., who said wind farms continue to affect weather radar signals.

“There are several wind farms (in the area). The wind farms interfere with the output of the radar, and the weather service has seen this all across the country. The NWS has built some algorithms into the radar to sort of accommodate for this,” said McClellan.

“The wind farms move the wind and dust and other particles that the radar picks up. It’s been very difficult for them to blank that out, and we still see the effects on our radar signals here in central Illinois.”

The wind energy industry can likely not do much to prevent the radar interference, he explained, other than to stop constructing wind farms in the line of Doppler radar signals.

As a former television meteorologist, McClellan remembers when the first wind farm was constructed in central Illinois. Almost immediately, disruptions of radar signals were common in the area of the 200-turbine wind farm, prompting him to attend seminars on the topic.

“Suddenly it was happening all over the place, so it has been a pretty big issue. With the new retrofit of the dual-Doppler systems, it is not as bad as it used to be, but it is still an issue,” he said.

Wind turbine interference with Doppler weather radar was still an issue in Oklahoma, the nation’s top wind energy-producing state behind Texas, as recently as October 2018. In a state known for its tornadoes, accurate forecasting can be a life-or-death issue, noted David Payne, a meteorologist for News 9 in Oklahoma.

“The data starts to look really, really fuzzy,” said Payne, adding when the skies are clear, wind farms don’t pose a problem; it’s when bad weather is moving over a wind farm that it becomes difficult to distinguish threats from false images.

“There are times when I’m looking at wind velocity data, at damaging winds or at an area of circulation, and I’ve gone, ‘Hang on a second – what’s real and what’s not?’”

The NWS has analyzed approximately 1,700 wind projects across the United States since 2006, but lacks the legal authority to stop any projects from moving forward. Instead, it passes along its concerns to local communities, project developers, and wind farm companies, hoping they take the NWS’ and local residents’ safety concerns seriously.

“They take it very seriously,” Mark Yates, Oklahoma director for the Wind Coalition, told News 9. “The industry is more than willing to cooperate with the NWS and NOAA (National Oceanic and Atmospheric Administration) to make sure that these situations are mitigated, because safety is the No. 1 concern.”

Those who use weather apps on their smart phones and other hardware can identify weather patterns that are actually wind farms by looking for a “radar loop” over a time lapse of the area, the Pantagraph reported. “It’s pretty easy to pick out; (the wind farms) don’t move,” said Kevin Lighty, a meteorologist with WCIA-TV in Champaign.