Are there multiple convergence zones in Washington state?
Yes. Convergence zones develop when winds split (usually when they encounter higher terrain) and then converge or come back 'together'. Perhaps the best known convergence zone develops over central to north Puget Sound when onshore winds split as they encounter the Olympic mountains, and then converge just east of Puget Sound, typically between Seattle and Everett. When winds are from the northwest, they may split around Vancouver Island, and then converge near Mount Vernon. And a similar (though smaller scale) convergence zone can develop just east of the Willapa Hills. And there are other, even smaller such zones that can occasionally occur here.