NWwindRetreatsStormAnimWhat happens to the North Pacific High when a storm targets the Bay Area:

by Mike Godsey

Today, Saturday June 22, we have a very unusual winter type storm system moving in from the NW. The storm system, which arrives Monday,  consists of an upper trough at about 18,000 ft. and below it 2 surface lows each with counter-clockwise spinning winds. Looking at the video I made below you can see in red the strong NW winds of the North Pacific High. This afternoon they will be sucked into the bay through gaps in the coast range by the pressure gradient to the Central Valley.

But tomorrow as the storm system slides towards the coast watch what happens to all that NW as the North Pacific High weakens and moves towards Southern California.

In the Bay Area this kills the NW winds and provides very UP AND DOWN unreliable southerly storm winds. In Southern California the storm brings unfavorable onshore flow, cooler inland valleys, a very deep marine layer and a weaker pressure gradient. While the NW wind becomes stronger at Jalama for most of Southern California the beaches will struggle with a Catalina Eddy.