Check out this ‘amazing’ rainshadow over Puget Sound
Dec 30, 2016, 7:57 AM
The North Puget Sound region got to experience a rainshadow on Thursday that is more often seen north of the Olympic Mountains.
The National Weather Service says the rainshadow was caught on radar around mid-day.
Imagery shows a cloudless “hole” over portions of Kitsap, King, and Snohomish counties, as well as over Whidbey Island.
Olympic rain shadow over N Puget Sound 1245pm.
— NWS Seattle (@NWSSeattle)
Here’s another graphic created by the Weather Service, detailing areas with lower relative humidity:
Olympic rainshadow forecast graphic. WSW winds 5K-10kft over Olympics. Colors show lower RH about where the rainshadow is.
— NWS Seattle (@NWSSeattle)
University of Washington Climatologist Cliff Mass says moisture from the west rose on the western side of the Olympics and sank on the eastern side.
“The result is a distinct hole in precipitation to the [east] of the Olympic barrier … a rainshadow,” . “As the air rises again on the Cascades, precipitation reforms.”
A rainshadow and surrounding areas. The result is “drier and brighter weather.” The rainshadow formed over North Puget Sound because of westerly wind, rather than the “typical south-southwesterly flow of winter,” according to Mass.
