A powerful storm system was expected to reach San Diego County overnight Thursday, bringing even more rain, wind, snow and a higher potential for flooding than its predecessor.
The heaviest showers were expected overnight, starting in the North County, with rainfall rates in some areas of about a half-inch to three-quarters-of-an-inch per hour. The excessive rainfall prompted the National Weather Service to issue a flood watch for the coast, valleys and mountains from Wednesday night to Thursday afternoon.
With about a half-inch already accumulated from the first storm this week, the second has the potential to add another inch to one-and-a-half inches to San Diego County's rain totals.
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Flooding
Heavy rain could swell rivers and flood poor-draining areas, which prompted San Diego County to staff up their water rescue team, which consists of six people specifically trained to respond to river floods. The San Diego Fire-Rescue Department also had three swift water rescue teams at the ready.
The storm was likely to heavily impact the Thursday morning commute. Drivers were asked to avoid traveling during the brunt of the storm where possible and to never cross flooded roadways, which could cause motorists to lose control, have car failure and get caught in rapidly rising water, San Diego County Fire Protection District said.
Areas like Mission Valley, Sorrently Valley and parts of the South Bay near San Ysidro are prone to flooding and drivers were urged to stay away and adhere to closures.
Rapid rain could also create mudslides and sinkholes in extreme cases, like a massive one that formed near Syracuse Avenue last year and continued to grow with every rain, according to Jason Nielsen, who lives nearby.
"My house is only about 30 yards from here and I worry about the hillside just collapsing in and getting worse. I don't see it getting any better especially as rainy season comes," Nielsen said.
The city of San Diego said the sinkhole was first reported in March 2024 and was caused by deteriorating metal pipes below ground. The pipes needed to be replaced but recent rain delayed repairs that were to begin this week.
"The walking trail was recently closed due to sinkhole expanding and construction fencing was re-installed to restrict access," a spokesperson for the city said.
Winds
On top of the rain, the powerful storm was expected to bring gusty winds that could topple tree branches or power lines. A wind advisory will be in effect for the valleys from Wednesday night through Friday morning, when wind gusts are expected to be in the 30-40 mph range for the coast and valleys. The mountains and desert could see wind gusts in the 45-55 mph range, and the desert was also under a wind advisory.
Snow
The second storm is much colder than the first and has the potential to dump a substantial amount of snow in the mountains. Snow levels could drop down as low as 3,000 feet by late Thursday into Friday morning and areas as low as Julian, Pine Valley and even stretches of Interstate 8 could see snow.
The NWS issued a winter weather advisory from Thursday morning until Friday morning for the county's mountains. During that time, driving could be slippery on snowy roadways.
"Higher peaks like Mount Laguna and Palomar Mountain could see more than 6 inches of snow," NBC 7 Meteorologist Greg Bledsoe said.
The first storm touched down overnight Tuesday, delivering a healthy dose of rain that lasted through Wednesday afternoon. Rain totals were approaching an inch in some places, including San Diego's airport, which had seen its single rainiest day in nearly a year.
In all, from Tuesday through Saturday, San Diego could see between an inch and two inches of rain, NBC 7 meteorologist Brooke Martell said.
There are chances for light showers again on Friday and possibly into early Saturday morning as well. Most of the weekend looks dry and slightly warmer.
