In the wake of the storm, a new Doppler for the Harbor


The biggest difference in atmospheric forecasting since the Great Coastal Gale of December 2007 storm is right on your TV screen when the weather news comes on.

Five years ago, the coast of Washington was cloaked in an atmospheric blind spot making it harder to predict weather cycles. Today, the green, red and blue blobs in the Aberdeen-Hoquiam area go all the way north to Taholah, indicating the rain that’s clearly visible through the windows of every home in the area.

That’s all thanks to the new Doppler radar at Langley Hill, put in place last year, thanks to a push from local community leaders and a congressional appropriation.

U.S. Sen. Maria Cantwell was able to secure about $9 million to help install the radar. Records from the National Weather Service show that it cost about $5 million to build the radar site, thanks, mainly to retrofitting a used Air Force Doppler radar with the latest technology. Most of the extra revenue was used to develop algorithms for a new technology called dual polarization.

Brad Colman, the head of the National Weather Service in Seattle, says the Doppler radar has been a success, creating extra data to help forecasters know when flooding could occur sooner and giving extra time to send out wind warnings.

Whether the Doppler actually could have helped for the December storm is up for debate, but it definitely helped advocates for the coastal radar make their case.

The Doppler, in particular, helps with the details of short-term forecasts.

“It gives us a better sense of what the front is,” Colman said. “But it’s not like we would otherwise just miss a wind storm if it wasn’t here.”

It might have given a better idea of how bad the storm would have been by allowing forecasters to predict even higher wind gusts a few hours before the storm hit the are, Colman said. But he has his doubts that the Doppler would have prepared the community any better for the devastation that eventually hit.

“The December storm was an eye opener for us because it helped us realize that there’s a big difference between making a forecast and making a forecast to a person making a decision — whether that’s someone deciding to go fishing or the power utility trying to figure out how to position their power trucks,” Colman said. “This really helped us do a better job figuring out we communicate the forecasts so that it is both understandable but also actionable. …

“This is a tough business,” he added. “Even with the Doppler, we will have errors in our forecast, but our job is to protect all of you and provide the best warning we can give you. That’s a pretty big responsibility.”

The Weather Service has developed a new “severe windstorm” warning, triggered by sustained winds of 60 mph with gusts to 90 mph. In the past five years, though, the Weather Service hasn’t had to use the new declaration.

Colman noted that if such an extreme event happens, the Weather Service has permission to use the Emergency Alert System, signaling a crawler across television screens and alerts on NOAA weather radios. Forecasters will also personally call every impacted Emergency Management division to personally “make sure they recognize the severity,” Colman said.

“We really needed a new way to let the community know that this is a kind of storm that you should really just hunker down and wait it out,” Colman said.

TECHNOLOGY

The Doppler uses a dual polarization technology, which send two beams to create a 3-D model of the precipitation coming down. This allows weather forecasters to know whether it’s raining or snowing and just how much, which helps with flood models, in particular. Colman says the technology has proven useful in sending out flood warnings earlier.

Colman points out that all of the Doppler stations west of the Rockies now use the dual polarization technology and the rest of the nation’s radars will see the change soon, too. At the National Weather Service’s headquarter in Norman, Okla., officials there have been able to use the new technology to get a better idea of debris being thrown about from tornadoes. Other uses have also been discussed.

The Doppler at Langley Hill is also among the first in the nation that lowered the radar beams sent out over the ocean to get a better idea of the storms coming in.

Current Doppler technology sends its beams up on a 0.5 degree angle. The Doppler radar lowered that bar to 0.2 degrees.

The Weather Service just finished a year-long pilot project of the lower elevation scan and received approval to continue it for another year.

Forecasters are able to switch from the 0.5 degree-angle to the 0.2 degree-angle and specifically look to see where the improvements are.

“There has been a benefit,” Colman said. “We were able to do at least one high wind warning a little earlier than we would have before.”

Colman says there are questions as to whether the technology will become the new standard. That’s a decision that could impact all of the weather service offices across the country.

Cliff Mass, the atmospheric sciences professor at the University of Washington, is optimistic the lower-elevation scan will lead to even better forecast models in the future.