Thunderstorms Likely to Continue in Southern California Through Friday

The National Weather Service (NWS) issued a storm warning Wednesday for Southern California.

In an update shared on social media, NWS predicted that thunderstorm conditions are likely to persist on Thursday evening and late at night in the San Luis Obispo and Santa Barbara counties. In Ventura County, the conditions will last till Friday afternoon. 

While the impacts are expected to be minor, there is a slight chance for higher totals and rates, the NWS added. 

Total rain is expected to range from 0.25 to 1 inch, with 1 to 2 inches in the mountains and hills between Wednesday night through Saturday, the weather service said. 

Snow totals are expected to range between 3 to 6 inches. 

Residents can expect wet roads, minor flooding of roads, and traffic delays, the weather service said. 

There is also an increased risk of rockslides and mudslides, the advisory added. Snowy and icy conditions can be expected on mountain roads. 

Radar Loop (Valid 828 AM):

– Light-locally moderate rain moving across SLO and SBA counties
– Rain will spread into Ventura/LA counties later this morning and afternoon
– Snow levels currently 7000+ feet will lower to around 6000 feet later today/tonight#CAwx pic.twitter.com/ZkvLUiwRY7

— NWS Los Angeles (@NWSLosAngeles) November 20, 2025

Record Rainfall in Santa Barbara

Several areas in Santa Barbara County experienced record rainfall this wet season, with rain in many areas receiving 400% to 500% higher than normal rainfall, according to the Santa Barbara County Flood Control District. 

The county witnessed one of the wettest starts to a water-year on record through November, said Santa Barbara County Flood Control District’s Senior Hydrologist Shawn Johnson. 

The county logged more than 8 inches of rain in November alone, with more rain predicted this week, Johnson said. 

The storm has led to changes in the storage levels at the county’s reservoirs. The Cachuma Reservoir is full and subject to spilling at an elevation of 750 feet. 

Water-year 2026 outperformed water-year 1983 as the wettest start on record in the City of Santa Barbara in the past 127 years, with 1983 also one of the wettest years on record in Santa Barbara County. 

However, a wet start to the water-year does not necessarily predict a wetter-than-normal year, Johnson said. Some of the very wet starts to the water-year (through November) include 1927, 1966, and 1983. These were the only years since 1900 that logged more than 7 inches of rain through November in the City of Santa Barbara. 

How to Stay Storm Ready?

Thunderstorms may cause floods in low-lying areas and places with poor drainage systems. Residents should be prepared for the movement of shallow debris flowing into recent burn areas. 

🌧️More rain is expected in #SantaBarbaraCounty tonight and thru Tues 11/18.
⚠️Brief, heavy downpours possible that may lead to additional flooding in roads and low-lying areas, minor mud/rock slides, and shallow debris flows in recent burn areas.
📍Info: https://t.co/YqDKvUy8WU pic.twitter.com/uYJAJYXUS7

— SBCountyOEM (@SBCountyOEM) November 16, 2025

ReadySBC advises residents to keep their mobile phone batteries charged, as well as a fully charged external battery pack in case of a prolonged power outage. 

Drivers should exercise caution while driving on wet, slippery roads. Roads and areas that appear to be flooded should be avoided.