Weather Blog

Dreamliner dodges the rain on its inaugural flight

Dreamliner dodges the rain on its inaugural flight
Image Courtesy FlightAware.com
Weather conditions were passable when the 787 took off on its inaugural flight Tuesday from Paine Field -- a ceiling of about 2,500 feet, 10 miles visibility, a light southeasterly wind, and dry weather.

But as the plane began its tests over the Strait of Juan de Fuca and Whidbey Island, rain moved in from the south, sort of boxing in the 787 and their likely attempts to do their flight tests in as best of weather conditions as possible.

Look at the image above, provided by FlightAware.com and see how the Dreamliner has been zig-zagging back and forth in a little dry slot over the Eastern Strait of Juan de Fuca. (Those colored blobs are rain radar echoes.)

This dry slot is likely the Olympic Rain Shadow doing its magic. As the air flows off the Olympic Mountains, it sinks and dries, usually helping break up the cloud cover a bit and improve visibility.

We also overheard a pilot remark on the scanner: "Wow, there's a good sucker hole over Tatoosh", which sounds pretty funny, but a "sucker hole" is weather and pilot speak for a break in the clouds -- like a blue hole among the gray.

It's called a "sucker hole" because it can lure pilots into thinking they have a clear spot to ascend or descend through a cloud layer, only to see it fill in around them or before they get there. (And "Tatoosh" is Tatoosh Island, off the northwestern tip of the state.)

In the press conference after the flight, the test pilots said the original flight plan was to go to Eastern Washington, but Boeing sent a plane on a weather check earlier Tuesday and found conditions were too turbulent over the mountains and in Eastern Washington to keep within parameters of their required tests.

An alternate weather check over the Strait showed more favorable conditions so pilots made the decision to conduct the tests there.