Puget Sound Convergence Zone

This convergence zone generally occurs between north Seattle and Everett and can cause updrafts and convection, which leads to a narrow band of precipitation.

[2] Puget Sound Convergence Zones, variable in both location and strength, tend to form in the general vicinity of central and southern Snohomish and northern King counties in Washington, from Everett to the Northgate neighborhood of Seattle.

The PSCZ has been suggested as the cause of greater precipitation over Glacier Peak relative to other mountains in the Cascades to the east of Puget Sound.

[5] On April 18, 2008, a strong and very unseasonable snow-producing Puget Sound Convergence Zone storm formed around Everett, and spread south throughout the course of the afternoon and evening.

[7] As the Zone slowly sank south of Shoreline into Seattle (past NE 145th Street), snow amounts began to taper off.