An upper level trough of low pressure is arriving in our area through the early morning hours bringing rain, cold temperatures, and mountain snow Wednesday and Thursday. Another system could bring additional rain on Sunday through early next week.
Very cold upper trough continues to drop south along the west coast. The forecast remains more or less on track plus or minus a couple hours on the timing. The cold front is going to zip through the forecast area at a rapid rate Wednesday morning, likely confining the period of heavier rain to about 3 hours. There will also be some gusty south to southwest winds during that peak time possibly even advisory level for a few hours across the coast and valleys and up to 50-60 mph in the mountains.
Rainfall rates and amounts with the front may be the highest of the entire event. Instability isn't great but can't rule out a clap of thunder or two. Hourly rates are anticipated to be between 0.25"-0.75". Minor flows are likely but much less confident in impactful flows.
This cold storm is anticipated to bring snow down to lower elevations around 3,000 ft. A Winter Storm Warning is in effect for the Ventura County and Santa Barbara County Mountains from 4AM Wednesday through 4AM Friday. Driving conditions will be danger with the potential for snow and high winds in the mountains.
The front is expected in San Luis Obispo County Tuesday night, and the early morning hours in Santa Barbara County and in Ventura County around 6AM. It is expected to bring between one to two inches. Strong souherly winds will also usher in the front. Creating a hazard along the fire lines of the Cave Fire. Once the front exits we will have showers last the rest of Wednesday and Thursday becoming heavy at times, and also bring the chance of hail.
Showers with possible thunderstorms will continue through Thanksgiving and Friday. Temperatures this entire time will be cool with highs only in the low to mid 50s.
Interesting pattern for the weekend into early next week. Weak ridging will develop over California Saturday, however the next system is not far offshore and it's tapping into a long fetch of moisture across the Pacific. The models have been struggling with the interaction between the trough offshore and the ridge but the trends appear to be favoring a return of wet weather to at least SLO/SB Counties by Saturday afternoon. It`s much warmer given the subtropical source and weak ridging aloft so this will not bring additional snow to the area.