Our warm weather will come to an abrupt end on Wednesday. Our ridge will flatten out in response to an approaching upper low from the Pacific Northwest. It will send a trough through California by the afternoon, increasing cloud cover. There is a very slight chance of light rain in northern San Luis Obispo County in the evening because of this.
Low temperatures will not change much with the interior in the 30s to 40s and coast in the 40s to 50s. High temperatures will drop - in some Central Coast areas by more than 10 degrees. The Central Coast will sit in the 60s, the South Coast in the low to mid 70s, and some valley areas also in the low 70s.
A high surf advisory at Central Coast beaches has been extended to 3:00 AM Friday. Breaking waves will grow to reach up to 14 feet by Wednesday. There is also an advisory at Ventura County beaches from 2:00 am Wednesday to 2:00 AM Friday with breaking waves up to 8 feet. Rip currents will be especially strong.
Onshore flow will likely bring some marine layer back to the Central Coast on Thursday. Skies will eventually clear out to allow for a mostly sunny majority of the day. Temperatures will continue to cool.
Temperatures will bottom out on Friday. Low clouds could hang on a bit longer through the morning hours. There will be good upper-level support for northerly winds on the Southwest Coast, possibly reaching advisory levels in the evening.
A ridge of high pressure will then build into the region on Saturday, starting a slow warmup. The mountains may get fairly gusty in Santa Barbara and Ventura Counties. Offshore flow will also develop, making for a fair weekend.