Bob Tisdale writes at Climate Observations:
After decades of no surface warming in the North Pacific as a whole, a prolonged weather event in the eastern extratropical North Pacific caused an unusual and unexpected warming there, raising sea surface temperatures in the North Pacific to new levels. That region of unusually warm sea surfaces in the eastern extratropical North Pacific has become known as The Blob . . .
The Blob had returned to the neighborhood of “Normal” values, but it has again made a very noticeable uptick. The Blob appears to be reemerging.
The Blog is associated with the Ridiculously Resilient Ridge which in the past has brought the state warmer winters reducing the snow pack in the Sierra. The Ridiculously Resilient Ridge is known to wobble producing both dry and wet spells in the Northern parts of the state.
In the past the Western ridge has forced Pacific storm systems to take make a sharp poleward turn 1000-2000 miles west of California, advecting copious warm/moist subtropical air toward much higher latitudes in Alaska and British Columbia, rather than in California. However, if the ridge is slightly further east, California will able to benefit from an occasional stream of moisture producing precipitation of the warm and wet variety.
If the Blob grows as currently indicated and the Ridiculously Resilient Ridge returns as it has in the past the best we can hope for is a warm wet winter, and not a warm dry winter. If the blob continues to grow the snow forecast is for a poor ski season and more drought for parts of California.