SoCal Storm Brings Flooding and Thunderstorm Risk to Surf Plans

Southern California’s Pacific storm has moved from forecast concern to overnight impacts: downpours brought debris flows and minor flooding, including flooded streets in San Juan Capistrano, according to KTLA’s Thursday, October 22 report. Meanwhile, the National Weather Service’s San Diego marine forecast says the system will linger over coastal waters through Friday, with a slight chance of thunderstorms Thursday.

I’m keeping the wave hunt secondary to the weather check. There’s surf in the Surfing Tomorrow forecast, but a promising set does not cancel a thunderstorm. Mother Nature has not agreed to respect our session windows.

Flooding is now part of the surf-trip equation

KTLA reported video of flooding Wednesday night near Via Banderas and Calle Conejo in San Juan Capistrano, downhill from the Norte Fire burn scar. That is a documented inland impact—not confirmation of a closure or contamination at any particular surf break.

Farther north, KTLA reported that a National Weather Service flood watch covered Santa Monica Mountains recreational areas, including Malibu, Pacific Palisades and Topanga, through Thursday afternoon. The station’s preliminary rainfall figures through 10 p.m. Wednesday ranged from roughly 0.25–0.5 inches in Los Angeles County coastal and valley areas to 0.5–1.5 inches in mountain and foothill communities, with additional rain expected.

Those are Los Angeles-area totals, not measurements for Orange County or San Diego beaches. I wouldn’t use them to declare your local lineup either contaminated or clear. Before loading the boards, check current beach-health notices, access restrictions and road conditions; don’t drive through flooded streets to chase a session.

South swell underneath unsettled weather

For waters from San Mateo Point to the Mexican border and out 10 nautical miles, the Weather Service’s 1:45 a.m. Thursday forecast calls for west wind at 10 knots and seas of 3–4 feet. Its wave breakdown includes a 3-foot south swell at 14 seconds, alongside smaller west and southwest components.

For Friday, that same forecast lists a 3-foot south component at 17 seconds, with southeast wind at 10 knots becoming southwest in the afternoon. Combined seas are forecast to build to 4–5 feet Friday afternoon. These are marine wave figures, not a promise of identical breaking-wave heights at every beach.

The bigger operational concern is the Weather Service’s thunderstorm guidance: any storm could produce erratic gusts, lightning, choppy seas, briefly heavy rain, reduced visibility and waterspouts. Its broader coastal synopsis also flags isolated northwest gusts exceeding 20 knots Friday.

My takeaway: don’t mistake a brief lull for an all-clear. A clean-looking face is a wave-quality observation, not a weather-safety assessment.

What it means for surfers

Here’s how I’m reading three local options through the Surfing Tomorrow forecast. These are modeled quality windows—not observations or permission to ignore warnings.

• Doheny State Beach: The Thursday best-window forecast is Good, 3–4 feet, 66/100, from 8–10 a.m., with 2-knot wind and a falling tide. The daily model lists swell direction at 188° and period at 12 seconds. Surfing Tomorrow’s break profile favors south-to-southwest swell and mid tide here. I would not turn Doheny’s appealing numbers into an automatic beginner recommendation during unsettled weather.
• Lower Trestles: Surfing Tomorrow projects Good, 4–5 feet, 75/100, for noon–2 p.m., with 4-knot wind and falling tide. Its cobblestone point favors south-through-west swell and low-to-mid tide, according to our break profile. I’d reserve this option for surfers comfortable with that size and bottom—and drop the plan if thunderstorms threaten.
• Windansea: Our forecast gives the noon–2 p.m. window Good, 3–4 feet, 74/100, with 4-knot wind and falling tide. Surfing Tomorrow identifies cobblestone over flat reef here and a preference for low-to-medium incoming tide, so the projected window is not a perfect textbook setup.

For Friday, Surfing Tomorrow highlights 6 a.m. at all three breaks, but the Weather Service still forecasts showers and a system moving through. I’m treating those early model peaks as watch-list entries, not appointments. At Lower Trestles or Windansea, lightning wins the argument. Keep the stoke; stay willing to sit one out.