I would have to say That is mold as well. Use a mix of Neem oil/hot water/ Silica @ 2ml each in a spray bottle 2X week to kill off the mold and reduce the chance of it happening again next year or the next batch.
What strain is that?
I can tell you a few that are far better suited for that area of Cali if you like. They have High mold resistance so wet rainy cold environments are actually perfect...