The rain shadow that protects Port Angeles and Sequim from storms that blow in off the Pacific lived up to its billing Monday.
As the rest of the Olympic Peninsula and Western Washington were buffeted and flooded, Port Angeles and Sequim was unaffected by winds.
Where rain was reported to be “horizontal” near Joyce, it was coming down vertically just 15 miles to the east.
Except for one 26 mph gust at 6:53 a.m., wind speeds recorded at the National Weather Service reporting station at William R. Fairchild International Airport in Port Angeles failed to reach 9 mph for the rest of the day Monday.
What exactly causes the rain shadow?
According to Scott Sistek, a Port Angeles native who prepares weather reports for KOMO-TV in Seattle, the Olympics push air upward as Pacific storms slam into the Peninsula from the southwest.
As the air lifts, it condenses and squeezes out the moisture – “think of it as the mountains acting like a sponge, soaking up and then squeezing out the rain,” Sistek says.
“That’s the reason there are vast rain forests on the southwestern side of the Olympics. They receive over 200 inches of rain a year.”
The air, now devoid of most of its moisture, continues over the tops of the Olympic mountains and comes down along the northeastern slopes into the Port Angeles-Sequim areas.
“And just like rising air condenses,” Sistek says, “sinking air dries out as it encounters warmer air near the [ground] surface. So you already have semi-dry air becoming even drier.”
