Tropical Storm Rachel expected to bring rain and wind to Southern California this weekend

The extreme October heatwave that pushed temperatures above 100°F in Los Angeles and San Diego for several days is ending, and forecasters are now focused on Tropical Storm Rachel. The National Hurricane Center has issued a tropical-storm watch for the Southern California coast from the Mexico border to the Orange-San Diego county line, an action taken only for the second time in the agency’s history.

Models show Rachel turning northward and possibly making landfall between Ensenada and San Diego, with a smaller chance of a more northerly strike in Orange County. The European Centre for Medium-Range Weather Forecasts ensemble gives the region about a 50% chance of tropical-storm-force winds, with some members indicating gusts over 50 mph and a few suggesting gusts up to 70 mph, especially in higher terrain.

The most certain threat is heavy rainfall that could trigger flash floods in the desert areas of southeastern California and western Arizona, while coastal flooding is expected to be moderate along the shoreline from Long Beach southward. The NHC warned that swells generated by Rachel could produce life-threatening surf, rip currents and isolated major coastal flooding through early next week.

The storm’s potential to maintain or slightly increase strength is attributed to record-warm Pacific sea-surface temperatures, which are more than 10 °F above average due to a combination of a strong El Niño, a prolonged marine heatwave and long-term climate warming. A mid-latitude trough moving into the region will also bring cooler, breezier weather and additional showers unrelated to Rachel.

Authorities advise residents in the affected coastal counties to prepare for possible flooding and dangerous surf conditions, and to stay tuned to local updates.