Progress Made On New Doppler Radar Site

The deal was signed by the site land owner and the agreement allows construction and clearing to begin immediately at the Grays Harbor County site, with a grand opening of the new coastal Doppler radar set for September.

“We’re going to have better lead times for warnings,” KIRO 7 chief meteorologist Rebecca Stevenson said. “We’ll be able to see within the storms, and be able to detect if they’re bringing powerful winds and how much rain will be in them.”

Dual polarization -- the latest technology in Doppler radar -- gives meteorologists views of both the horizontal and vertical dimensions of oncoming storms, giving them a better look within storms that threaten rain and snow, Stevenson said.

WATCH IT: The Dual Polarization Difference

"The dual polarization technology brings a couple of unique features," Stevenson said. "One (is) where the snow level is -- where snow transitions into rain and vice versa. It also gives more accurate rain rate estimates, which help in flood forecasting."

The coastal radar system was advocated by local meteorologists after a powerful storm in December 2007 blasted Western Washington, pounding coastal areas and flooding the Chehalis River. The storm killed eight people and caused $1 billion in damage. Stevenson said that because of a lack of coastal radar, forecasters didn't have a good idea of the storm's intensity.

Stevenson recently traveled to Norman, Okla., to get a firsthand look at the only dual polarization radar currently in operation in the country.

"Current radars have no way of knowing different precipitation types. In other words, if it's rain or snow, it doesn't know the difference," Paul Schlatter, a National Weather Service meteorologist instructor, told Stevenson.

"With dual polarization technology, we are able to get a better picture of the type of precipitation out there so we can tell if it's rain, if it's snow, or a mixture of rain or snow," Schlatter said.

Within 18 months, all Doppler systems nationwide will be equipped with this latest technology.

Washington state will be the first state to be completely covered with the upgraded technology, Stevenson said.