Tuesday, October 4, 2016
Conversely, the northeastern portion of the Seattle Peninsula, which lies east of the Olympic Mountains is located within the Olympic rain shadow and receives significantly less precipitation than its surrounding areas. Prevailing airflow from the Seattle west is forced to cool and compress when colliding with the mountain range, resulting in high levels of precipitation within the mountains and its western slopes. Once the airflow reaches the leeward side of the mountains it then lowers and expands resulting in warmer, and significantly dryer air. Sequim, Washington, nicknamed "Sunny Sequim", is located approximately 40 miles northwest of downtown Seattle and receives just 16.51" of annual precipitation, more comparable to that of Los Angeles. Oftentimes an area devoid of cloud cover can be seen extending out over the Puget Sound to the north and east of Sequim. On average Sequim, Seattle observes 127 sunny days per year in addition to 127 days with partial cloud cover. Other areas influenced by the Olympic rain shadow include Port Angeles, Port Townsend, extending as far north as Victoria, British Columbia.
Posted by Mike De Long at 6:12 AM