Rain will arrive midday on Friday and last through the weekend
Thursday night will be dry and cloudy. It may even be a little windy at times along the South Coast. The marine layer will be deep on Friday morning, and more upper-level clouds will start to fill in. Low temperatures on Friday will be in the upper 30s to 40s, and highs will drop by several degrees, moving to the upper 50s or low 60s.
Light to moderate rain will reach the Central Coast by the early afternoon and move southward in the late afternoon or evening. It will be very fairly steady overnight, and eventually turn more showery by Saturday afternoon. Showers will linger into Sunday and taper off, though there could be a second boundary that develops. There is a slight chance of thunderstorms or hail, and as such, rain may be briefly heavy.
There is a flood watch for all areas except the northern Ventura County mountains from Friday evening through Sunday afternoon. Most rain rates will be a quarter to half inch per hour, but there may be isolated rain cells falling at up to three quarters of an inch per hour. We expect 1 to 3 inches of rainfall in coastal areas and 3 to 6 inches in the mountains and foothills. South-facing slopes will see the most rain with enhancement from the wind.
Mountains will also get snowfall, accumulating 1 to 2 feet of snow above 6,000 feet, 6 to 12 inches above 5,000 feet, and 2 to 6 inches above 4,500 feet. There is a winter storm watch in the Santa Barbara and Ventura County mountains from Friday afternoon to Sunday afternoon.
Southerly winds will be strong during this system, picking up at first on Friday afternoon. It will be especially strong in interior and mountain areas of SLO and Santa Barbara Counties. With saturated soil and extra wind, there is a higher potential for downed trees or power outages.
There is a high wind watch in the San Luis Obispo County mountains from Friday afternoon to late at night. Gusts will be up to 60 mph. There is a wind advisory from 3:00 pm Friday to 6:00 am Saturday on the Central Coast and in the SLO County interior valleys with gusts up to 45 mph.
There is a high surf advisory on the Central Coast until 9:00 am Sunday with breaking waves from 8 to 12 feet, and local sets up to 15 feet. Rip currents will be strong.
Conditions will dry out and skies will clear out on Monday. Temperatures will rise by a few degrees. the warmup will continue into midweek, and some interior valleys could punch up to the mid 70s for high temperatures.
