By Reginald Stanley. Posted December 13, 2020, 1:51 PM.

Stable northwest flow is responsible for a number of disturbances bringing onshore and offshore flow to Southern California this week, while bringing rain and snow to Northern California.

The Santa Ana Wind events last week were followed by strong onshore flow and a deep marine layer Saturday, evening bringing drizzle to some communities. The weather pattern flipped back to offshore flow on Sunday, sending humidities crashing down and elevating fire danger once again. High clouds were drifting over the region by Sunday afternoon. An incoming trough will flip this pattern back to onshore flow yet again Monday, ushering a return of the marine layer as the trough digs into Southern California and Arizona late Sunday night. The upcoming onshore flow pattern will be more consistent throughout the week, with trace amounts of precipitation possible late Sunday night into early Monday morning, and potentially Thursday-Friday. Temperatures are expected to remain within a few degrees of average on either side over the course of the week.