Tropical Storm Rachel Floods SoCal Coast Under Rare Watch

San Diego is under a tropical storm watch for only the second time on record as Tropical Storm Rachel churned toward northern Baja California late Saturday, while seawater was already flooding streets in Newport Beach, where city officials declared a local emergency on Friday.

Rachel was centered about six hundred miles south-southwest of San Diego early Saturday, with maximum sustained winds near 60 miles per hour and a track moving northeast at about 20 miles per hour, according to the National Hurricane Center. Forecasters expected the storm to reach the area near the United States-Mexico border late Saturday or early Sunday. By Saturday night the system had weakened into a post-tropical cyclone, reported NBC 7 San Diego, but the rain, wind and surf it was pushing ahead of it were still building.

In Newport Beach, the damage arrived before the storm did. A swell roughly double the forecast size blew through the sand berms at the Wedge on Friday, flooding streets on the Balboa Peninsula from about 21st Street to 6th Street. Water ran knee-high across several blocks, stranded vehicles, and crept toward homes set back from the beach, reported Surfer magazine, which has covered the coast for decades. City crews spent the day rebuilding berms, running pumps and opening tide valves to drain flooded streets. According to ABC7, around fifteen to twenty blocks flooded, and the morning high tide ran about a foot and eight inches above its predicted level. One city council member described it as the worst flooding he had seen in twenty years on the Peninsula.

A warning almost never issued for California

The National Weather Service extended its tropical storm watch to all of San Diego County and adjacent coastal waters on Friday. The only previous watch of this kind came with the remnants of Hurricane Hilary in 2023, the first year the weather service began issuing these alerts for Southern California. Earlier tropical systems had reached the area before then, the NWS San Diego forecast office noted, but none triggered a watch or warning. A tropical storm has not made an official landfall in Southern California since 1939, according to historical records cited by JQJO.

Rachel was expected to come ashore in northern Baja California early Sunday morning, according to CNN. Even a miss by the center would matter little for Southern California, forecasters said, because the storm's moisture and swell arrive regardless. South swells generated by Rachel, combined with tides running over seven feet and elevated water levels, were already producing beach erosion and flooding along parts of the San Diego and Orange County coasts, the National Hurricane Center said. Surf was expected to peak at six to nine feet on Sunday.

Inland flood risk stretches across the Southwest

The Weather Prediction Center issued a Moderate risk of excessive rainfall, level three of four, covering Southern California, northwestern Arizona, southern Nevada and southwestern Utah for the 24 hours ending Sunday morning. A further Moderate risk area was set for the following day as Tropical Storm Rachel's remnant circulation carried tropical moisture northeast toward the Great Basin. At that level, forecasters expect numerous flash flood events with significant impacts possible.

The hurricane center forecast 1 to 3 inches of rain across portions of the Southwest, with localized amounts up to five inches. San Diego and Las Vegas could each see an inch or more, which is about double what San Diego normally gets in all of October and triple the typical October total in Las Vegas, reported CNN. Desert ground cannot absorb intense bursts of rainfall quickly, which is why flood watches were issued even for areas that will see what looks like modest totals. A flood watch was in effect for the Coachella Valley through Sunday evening, and flash flood warnings covered parts of San Diego, Riverside and Imperial counties overnight Saturday, according to the National Weather Service.

Winds added to the threat. Peak gusts around San Diego were expected early Sunday morning, running 25 to 40 miles per hour at lower elevations and 50 to 70 miles per hour in the mountains, said the National Weather Service, with the stronger end of the range possible if Rachel took a more northerly track. Gusts of 45 to 55 miles per hour were forecast inland across parts of Arizona, southern Nevada and Utah.

Why this storm can reach so far

Tropical storms rarely threaten Southern California because cool ocean water usually saps their strength. This year is different. A strong El Niño has kept Pacific waters unusually warm, allowing Tropical Storm Rachel to hold together on its approach, and a powerful Kelvin wave linked to the same pattern has raised the baseline sea level along the West Coast, according to the Orange County Coast report citing the National Weather Service. Starting each high tide from a higher level lets waves and tides reach farther inland and overwhelm berms more easily.

The National Weather Service said the greatest impacts were expected Sunday morning from the combination of Rachel's increased swell, onshore winds and exceptionally high tides. A coastal flood warning for the Orange County coast ran through Sunday afternoon, and a coastal flood advisory remained in effect through Tuesday afternoon, giving residents several tide cycles of elevated risk. Related: Hurricane Isaias Rises Late Over a Hotter Gulf, on how record-warm water fueled this season's record-late first hurricane.

What officials are telling residents

Newport Beach officials warned that the worst might still be ahead, with Sunday morning's higher tide and bigger swell expected to pose the greatest threat. Residents and drivers were urged to avoid the flooded Peninsula, and people in flood-prone areas were told to move vehicles to higher ground. At Crystal Cove State Park, California State Parks evacuated 26 historic cottages as the surf chewed at the shoreline, the Orange County Coast report said.

City crews and residents across the region spent Saturday preparing for water, wind and high tides expected early Sunday. Rachel is among several systems spinning in an active eastern Pacific: Hurricane Simon, a Category 4 storm with winds near 150 miles per hour, was also approaching Mexico's Pacific coast. For Southern California, the immediate question is the Sunday morning tide cycle, when forecasters say Rachel's surge, the moon-driven tides and the already elevated sea level will combine. Read more: CNN: San Diego under rare tropical storm watch and Surfer: Newport Beach flooding emergency.