North American West Coast healthy rainy seasons need normal sea ice extent

~ Long ignored sea ice climate permutations manifest big time

~ We look at mainly the North Pacific

~ Current El-Nino can only exacerbate bent Northwards general circulation 

   Although its pleasant climate has apparently nothing to do with ice and snow, there is a rainy season in sunny L.A.  California,  having everything to do with a colder climate to the North.   Through long time late autumn  cycles,  the North got significantly cold mainly because Siberia and Alaska was imbued in longer dark days creating a net lost heat to space.    But sea ice cover within Arctic Ocean  and very North Pacific is an equivalent to land,  also greatly cooled the North,  absent sea ice ,  replaced by warmed sea water,  winter's cold punch  has dulled,  especially since 2007,  but very much seriously lately:

NOAA November 12 2018 sst anomalies  Further North, they call it the blob,  the great North Pacific surface warming has a lot to do with the lack of cooling during winter,  because there is a feedback loop between less sea ice extent and more low clouds.  Even less radiation leaving to space favors the presence of huge Cyclones :  

The implied late autumn black line should be the location of the polar jet stream given the latest sea ice extent losses.  Fortunately often present massive North Pacific cyclones bend the jet to its South (red line),  but this means the North Pacific is covered with clouds for vaster periods,  not cooling the sea surface to space.  This also implies a shift in rainy season of the West North American coast,  well Northwards,  this current climate scene was not always so  :

  Given a normal sea ice scenario,  pre 1998,  a shift in the Polar jet stream well to the South of its latest decadal tendencies  gave the recorded fall and winter  coastal rainy seasons climate which was importantly wetter than latest recent years.   WD November 15 2018