Puget Sound Convergence Zone Puget Sound Convergence Zone The Puget Sound Convergence Zone (PSCZ) is a meteorological phenomenon that occurs over Puget Sound in the U.S. state of Washington. It is formed when the large-scale air flow splits around the Olympic Mountains and then converges over Puget Sound. This convergence zone generally occurs between north Seattle and Everett and can cause updrafts and convection, which leads to a narrow band of precipitation. A second, weaker convergence zone can occur between approximately Victoria, British Columbia, and Bellingham, Washington, over the San Juan Islands, as a result of southwesterly air blowing from the Strait of Juan
Lake Washington is now the primary source of water for Lake Washington. In addition, there are numerous small creeks and rivers which feed the lake, including: Before construction of the Lake Washington Ship Canal in 1916, Lake Washington's outlet was the Black River, which joined the Duwamish River and emptied into Elliott Bay. When the canal was opened the level of the lake dropped nearly nine feet (2.7 m). The canal to the Puget Sound became the lake's sole outlet, causing the Black River to dry up and disappear. Concrete floating bridges are employed to span the lake because Lake Washington's depth