Southern California faces its first significant storm of the season, bringing heavy rain, potential flash flooding, and a rare coastal tornado threat from Wednesday through Thursday, October 21–22, 2026, as meteorologists warn of rising rainfall totals and hazardous conditions across burn scars and major highways.
National Weather Service Issues Flood Watches Across Los Angeles and Regional Highways
An updated flood watch covers the Malibu coast and the eastern and western Santa Monica Mountains, taking effect Wednesday afternoon through Thursday afternoon. Forecasters expect the bulk of the moisture to concentrate in the Los Angeles basin Wednesday night and continue into Thursday morning.
The National Weather Service issued the watch specifically for areas including Malibu, Malibu Bowl, Pacific Palisades, and Topanga. According to forecasters, the targeted watch was declared because computer models indicated the highest rain rates would hit those specific zones at around 0.75 inches per hour.
A rare risk for tornadoes and severe weather exists across both the Desert Southwest and the Southern California Coastline today. Ensure you have multiple ways to receive weather alerts and warnings!https://t.co/o5cxJlONPR pic.twitter.com/ijS2c9ega8
The 5 freeway through Grapevine, West Side Mountains South of 198, Buttonwillow, Lost Hills, I-5 Bakersfield South End, San Joaquin Valley, Kern River Valley, Piute, Walker Basin, Tehachapi, Frazier Mountain Communities, Indian Wells Valley, and Mojave Desert Slopes are among the other locations included in the flood watch.
Flash flooding caused by excessive rainfall from storms training over the same area.
NWS Hanford CA
Poor drainage systems in urban sectors may also back up, causing extensive street flooding, while low-water crossings, storm drains, and ditches risk becoming clogged with debris.
A moderate storm is expected to impact Southern California Wednesday through Thursday. Isolated to scattered thunderstorms are possible. Minor flooding and debris flows possible near recent burn scars. #CAwx #SoCal #LAWeather pic.twitter.com/vbNxtzCUKV
Rainfall Projections and Burn Scar Hazards in Southern California
Downtown Los Angeles could pick up 1 to 1.5 inches through Thursday night, potentially marking the city’s wettest October since 2009. Across the wider region, areas like Orange County and western portions of San Bernardino and Riverside counties face a chance of rain starting early Wednesday, with rain chances increasing further during the night and pushing south into San Diego County.
Across Los Angeles County, daytime highs generally range from the mid-60s to the lower 70s.
California is continuing our prep work for El Niño's arrival and the dangerous flooding those storms might trigger over the next few months.Now is the time to look up your local flood risk, sign up for alerts, and make an emergency plan. https://t.co/LfGKPVU1h4
We are seeing rain totals trending upward,
Bryan Lewis, meteorologist
Bryan Lewis, a meteorologist, also stated that the peak of the storm would probably be from late Wednesday morning through late Thursday morning.
The intense downpours raise acute concerns for debris flows across recent wildfire burn scars. Bryan Lewis noted that minor debris flows can be expected in the area. Local officials are monitoring vulnerable terrain around the Bryson Fire, Palisades Fire, and Eaton Fire burn scars in the Santa Monica Mountains and Pasadena areas, alongside older burn scars left by the Bridge and Line fires from 2024.
Rare Tornado Threat and Severe Marine Conditions Along the Coast
Forecasters note a low-end risk of severe weather accompanying the system. The National Weather Service placed the coast from Monterey to Orange County at a marginal risk of severe weather on Wednesday, carrying a small chance of tornadoes generated by small, intense thunderstorms.
Forecasters calculated a low probability of a short-lived tornado as the counterclockwise-spinning low pressure system moves onshore. The current system is similarly influenced by an El Niño environment that has warmed ocean temperatures up to 10 degrees above normal, adding extra heat and moisture.
Marine conditions are deteriorating concurrently.
Pasadena Mobilizes Crews and Sandbags for Incoming Weather
Municipal agencies across the region mobilized ahead of the incoming weather. In Pasadena, road crews and utility workers prepared for disruptions while the city offered self-serve sandbags at two fire stations, while supplies last. Pasadena Water and Power readied emergency crews for potential outages and drainage clearing around critical infrastructure.
Severe thunderstorms including large hail and tornado risks are expected on Wednesday especially across Arizona and nearby parts of the Four Corners area and Lower Colorado River Valley. A localized severe risk may also exist along the coast of central/southern California. pic.twitter.com/edt77Tv9Ww
Pasadena detailed a coordinated response plan involving Public Works, Parks, Recreation and Community Services, the Economic Development Division, and Pasadena Water and Power. Public Works personnel staged emergency equipment, standby crews, barricades, K-rails, traffic signs, and portable message boards to handle potential road closures and detours.
Dry weather is expected to return over the weekend, accompanied by offshore winds. Temperatures could climb back into the 80s in some areas, though the anticipated Santa Ana event is expected to be considerably weaker than the hot wind event from the previous week.