A powerful storm system slid down the spine of California, pushing heavy rain through the Bay Area and Los Angeles before touching down in North San Diego County Wednesday afternoon.
Flash flooding, thunderstorms, and inches of snowfall were possible between Wednesday and Friday, adding to already hazardous driving conditions as millions of travelers tried to reach Thanksgiving holiday destinations.
The first sign of showers reached North County communities like Oceanside, Carlsbad and Julian just before 1 p.m. and continued to push southeast. Meanwhile, as other parts of San Diego County waited for the storm to hit, winds began to increase into the 20 mile-per-hour range.
As of 4 p.m. Wednesday, Carlsbad's half inch of precipitation led all coastal areas. The San Diego Airport saw .20 inches of rain and San Ysidro saw less than an inch.
Miramar Lake topped valley areas with .37 inches and Palomar Mountain saw just over a half inch.
During the storm's three-day stint over the Southern California region, San Diego could see more than three inches of rain and up to six inches of snow, NBC 7 Meteorologist Sheena Parveen said.
The impact could be dangerous for drivers on what AAA predicts will be the busiest travel holiday in 14 years.
While Thanksgiving is one of the busiest times for travel all year, it's also one of the deadliest, the California Highway Patrol warned. The CHP said it would ramp up enforcement due to the winter weather.
"For those three days we will be in ‘Weather Alert’ around here, travel will be hazardous," Parveen said in NBC 7's First Alert Weather forecast. "Thanksgiving Day itself looks very messy travel-wise."
Several watches and warnings were issued in anticipation of the forecasted winter weather. A Flash Flood Watch was in effect for the coast, inland valleys and foothills from Wednesday morning to Thursday evening. The mountains were under a Winter Storm Watch from late Tuesday to Friday evening.
During these times, rain could fall at a rate of a half-inch per hour, which has the potential to create isolated flash flooding in steep terrain and areas with poor drainage.
The most damaging rain was expected on Thursday. The NWS said the areas of Oceanside, Vista, Carlsbad, Encinitas, Chula Vista, National City, San Diego Escondido, El Cajon, San Marcos, La Mesa, Santee, and Poway should be on alert.
Several locations were handing out free sandbags to help residents protect their property.
Families in one section of University Heights were loading up on sandbags because they say layers on top of layers of new pavement on their street have shortened the curbs, and now heavy rain sends water gushing into their yards and homes.
"A full day of rain or couple of days of rain and there is no doubt that the water would just overwhelm the homes that are susceptible to it," one resident explained.
Neighbors gathered sandbags and built a makeshift dike to control the flow of water away from their porches. Though stressed, they're not giving away their holiday spirit.
"I am grateful regardless, I would just like to see if the city can do anything to help protect us," one neighbor said.
In Chula Vista, people were lined up to use a machine known as a "sand bag hopper" to fill bags up with gravel.
Coastal flooding is also possible as higher-than-usual tides, commonly known as king tides, hit the shore through Thursday. Imperial Beach had signs posted warning residents of potential flooding.
Mountains as low as 3,000 feet could see a dusting of snow, while mountains above 4,000 feet could receive up to six inches, Parveen said. Ranges above 5,500 feet could get up to three feet of snow.
Drivers were urged to check mountain road conditions before heading out and to travel with an emergency supply kit. While no snow tire requirements were issued as of Monday, it was a possibility once the storm hits.
The California Highway Patrol reminded snow seekers that trespassing on private property to enjoy fresh snow is illegal.
The county isn't expected to dry up until late Friday and some lingering showers and cold weather could stretch into the weekend. Drier conditions are expected next week, Parveen said.