Thursday evening forecast September 23rd

Temperatures are cooling down gradually into the weekend, due to stronger onshore flow. Marine layer clouds are likely to expand to areas south of Point Conception, prompting widespread cooling. Plus a system will prompt further cooling into next week, leading to below average temperatures through the middle of next week.

As onshore flow strengthens temperatures cooled down, with most areas down by 4 to 8 degrees. As low level clouds expand, cooling will mainly arrive across the interior valleys and areas that dealt with offshore trends. Overall looking at little change from today, with most coastal areas warming near seasonal conditions. Daytime highs near coast will warm in the 60s to 70s, inland areas looking at the 70s to 80s.

A cooling trend will likely continue through the weekend across the valleys, as onshore flow gets stronger. A weak system near Baja California is expected to shift further east, into Arizona. This will bring a slightly weaker onshore flow on Monday as the system slidse out.

However, temperatures will drop further early next week, as a low pressure system over the Pacific Northwest prompts a strong onshore flow through Wednesday. This could bring a deeper marine layer and maybe some drizzle.