A strong October storm is moving toward Southern California, with forecasters warning residents of widespread rain and a heightened risk of localized flooding. The National Weather Service (NWS) indicated Tuesday that the approaching system could deliver rainfall totals ranging from one to two inches in some areas, with the possibility of heavier downpours.
Rainfall could commence as early as Tuesday night, though the most significant threat of heavier showers and thunderstorms is anticipated from Wednesday night through Thursday. The NWS described the system as "a pretty potent storm for October" that appears headed for Southern California.
Current projections suggest at least a half-inch of rain over the two-day period, with most areas likely receiving closer to an inch. Some locations could see as much as two inches. Forecasters noted that locally higher totals cannot be ruled out if stronger showers or thunderstorms develop, with peak rain rates potentially reaching up to .75 inches per hour. This increased concern about hazardous rainfall compared to earlier projections could necessitate a flood watch.
The storm, which was observed off the Oregon coast on Monday, is expected to track south along the California coast before moving inland between central and Southern California on Thursday. However, forecasters noted that the exact timing and rainfall amounts remain uncertain due to the low-pressure system being partially separated from the stronger jet stream to the north.
This weather system is also predicted to bring a notable drop in temperatures, following several days of unusually hot conditions and powerful Santa Ana winds. Temperatures began cooling over the weekend as offshore winds subsided, with additional cooling expected Tuesday. The NWS stated that temperatures would fall below normal Tuesday for the first time in several days. Wednesday and Thursday are expected to be cloudy and cool, with daytime highs generally in the mid-60s to lower 70s across much of Los Angeles County. Orange County is also anticipated to experience cooler temperatures and periods of rain, with thunderstorms possible as the storm traverses Southern California.
Marine conditions are also expected to deteriorate from Wednesday into Thursday, with rain, thunderstorms, and isolated waterspouts possible in coastal waters. Forecasters cautioned that thunderstorms over the ocean could produce lightning, gusty and erratic winds, small hail, and choppy seas.
A beach hazards statement remains in effect through late Thursday night for portions of the Los Angeles County coastline. Elevated surf and dangerous rip currents are expected, with minor beach erosion and tidal overflow possible in low-lying areas.
Looking ahead, dry and warmer weather is anticipated to return Friday and continue into next week. Forecasters indicated that offshore winds could return over the weekend, although any anticipated Santa Ana event would be considerably weaker than the one that brought strong winds and unusually hot weather to the region last week. Temperatures could climb into the 80s in some areas over the weekend, according to the NWS. The NWS also confirmed the storm is unlikely to produce snow below 8,000 feet.
