The ocean conditions off the PNW and Alaska are control primarily by the Pacific Decadal Oscillation or PDO, this phenomenon dictates our ocean conditions.

http://www.atmos.washington.edu/~mantua/REPORTS/PDO/PDO.pdf

Evidence gleaned from the instrumental record of climate data identifies a robust, recurring
pattern of ocean-atmosphere climate variability centered over the mid-latitude North
Pacific basin. Over the past century, the amplitude of this climate pattern has varied irregularly
at interannual-to-interdecadal time scales. There is evidence of reversals in the prevailing
polarity of the oscillation occurring around 1925, 1947, and 1977; the last two
reversals correspond with dramatic shifts in salmon production regimes in the North
Pacific Ocean. This climate pattern also affects coastal sea and continental surface air
temperatures, as well as streamflow in major west coast river systems, from Alaska to California.