Parts of Southern California are expected to be hit by heavy rain, thunderstorms and a possible tornado, while the Golden State braces for its biggest rainstorm since August, when Tropical Storm Hillary made landfall.
San Francisco has already experienced downpours and issued flood advisories, with rain expected to become lighter there after Wednesday.
The National Weather Service said the storm is expected to bring two to four inches of rain along the coasts and valleys through Friday, and perhaps even Saturday morning.
Heavier showers continued north of Los Angeles Wednesday morning, with most areas receiving light to moderate rain. Thunderstorms, high winds and a possible tornado are also expected.
Forecasters have predicted the most dangerous conditions will begin to impact Southern California Wednesday afternoon through Friday.
A major rainstorm is expected to hit Southern California late Wednesday and possibly last into Saturday morning. Downpours already reached San Francisco on Tuesday
The chance of thunderstorms and lightning will also be “favorable,” with a small chance of a small, “short-lived” tornado, the National Weather Service said in a severe weather warning.
The weather bureau also said the areas most at risk are Los Angeles, Ventura and southern Santa Barbara counties. Dangerous lightning, high winds, small hail and a possible tornado are all expected from the storm.
They have urged residents to seek shelter “in the innermost room of a building” and stay far away from windows if a tornado or strong winds develop.
Winds are expected to reach speeds of 50 to 100 km per hour, but the strongest winds will remain in the mountain areas.
Although threatening weather is forecast, KTL Meteorologist Henry DiCarlo said the storm is likely to move slowly.
“This is already a slow-moving system, so if these cells stay above you for 15 minutes, maybe 30 minutes, you could get a half inch of rain,” DiCarlo said.
The Inland Empire and Orange County are also expected to receive measurable amounts of precipitation.
KTLA reported that four to eight inches of rain could fall in the foothills and mountain areas, while some areas could see four or more inches of rain.
Heavy rain poured down busy Highway 101 in the San Francisco Bay Area on Wednesday
People in Alamo Square looked out at 'The Painted Ladies' row of Victorian houses amid a rainstorm in San Francisco on Tuesday
Tropical Storm Hillary hit Southern California in August after traveling into the Golden State from Mexico. It was originally a Category 4 hurricane
In August, Southern California was battered by Tropical Storm Hillary after it made landfall in Mexico over the northern Baja California Peninsula with maximum sustained winds of 65 miles per hour.
According to the National Hurricane Center, the system then moved from north to northwest at a speed of 25 miles per hour.
Two people from Mexico were killed in the storm, when one of the victim's vehicles was swept away near Santa Rosalía after catastrophic flooding swallowed up parts of Mexico's Baja California peninsula.
The tropical storm was initially a Category 4 hurricane in the Pacific Ocean before barreling into Central America on August 12.
The storm subsequently weakened to a tropical storm when it struck the coast of Manzanillo, Colima, a city in Mexico, on August 16.
It strengthened and became a hurricane again before weakening again as it struck California.
The anticipation of the severe storm left grocery store shelves empty due to the urgency of a community unfamiliar with such storms.
Only canned fish and in some cases plain white bread were still available in traditionally stocked stores.
California Governor Gavin Newsom declared a state of emergency, saying, “We are mobilizing the entire government as we prepare for and respond to this unprecedented storm.”
While a majority of people sought shelter from the storm, others braved the wet conditions to bask in the storm's precursor, which had grown to the size of the state of Arizona.
Governor Gavin Newsom declared a state of emergency for much of Southern California to support the response and recovery from Tropical Storm Hilary ahead of the summer storm
Volunteers and members of the Long Beach Fire Department fill sandbags on Belmont Shore Beach before Hilary on August 20, 2023
A vehicle splashes through puddles along a street that begins to flood in the Van Nuys section of Los Angeles as Tropical Storm Hillary made landfall in Southern California
A few stragglers could be seen in raincoats and parasols as the rough seas battered a pier in Imperial Beach, while some walked along the shoreline while they could.
Photos and videos of flooded roads, angry coastlines and hardworking crews preparing for Hillary were shared all over social media.
Although California doesn't normally see rain, state data showed annual measured rainfall for this year was 141 percent of the typical annual amount.
Dan McEvoy, a researcher at the Western Regional Climate Center, said this year's high tide rankings are the 10th wettest since precipitation records began 128 years ago.
Rainfall records for California run from October 1 to September 30 each year. A flood watch is in effect for Southern California for three straight days due to expected rain.