• A series of storms is expected to bring heavy rain, strong winds, and potential flooding to California through the holiday weekend.
• The most intense rainfall is forecast for Tuesday night into Wednesday, with some mountain areas possibly seeing over an inch of rain per hour.
• Forecasters warn that saturated soil increases the risk of mudslides and debris flows, even days after the rain has stopped.
• Residents are advised to clear gutters, drive cautiously on slick roads, and stay informed about local weather alerts.

A flood watch is in effect in Stockton and San Joaquin County through the day after Christmas as rain and gusty winds are expected to create hazardous driving conditions, according to the San Joaquin County Office of Emergency Services.

An atmospheric river moving across California is also expected to bring colder temperatures, increasing the risk of hypothermia and other cold-related illnesses, particularly among the unhoused community, county officials said.

“The County stands ready to respond to flooding, power outages, and other storm impacts,” said Tiffany Cacho, Director of Emergency Operations, Office of Emergency Services. “We are working with our cities, partners, and the community to keep everyone safe, and we encourage residents to do their part and take steps now to prepare their homes and families.”

In Stockton, emergency shelters can be found at:

• Gospel Center Rescue Mission, 445 S. San Joaquin St., (209) 466-2138

• St. Mary’s Dining Hall and Shelter, 545 W. Sonora St., (209) 467-0703

The city of Stockton is making free, self-fill sandbags available at the following locations (Must show proof of Stockton address):

• Stockton Soccer Complex, 10055 N. SR-99, W. Frontage Road
• Weber Point, 221 N. Center St.
• Van Buskirk Park, 1740 Houston Ave.

San Joaquin County residents can sign up for SJReady Alerts at www.sjready.org or text SJStorms to 888777 to receive emergency notifications. For information on sandbag availability and warming center locations in San Joaquin County, check www.sjready.org, your city’s website or call 2-1-1.

Travelers planning trips to or from Tahoe, or across Interstate 80 and Highway 50, should closely monitor forecasts and road conditions, especially for travel late Tuesday night through Christmas Day, the National Weather Service advises.

Atmospheric river to bring heavy rain through Christmas holiday

Another round of storms is moving across California this week, bringing periods of heavy rain, strong winds and flooding concerns to large parts of the state as an active weather pattern settles in.

Forecasters say the most intense rain is expected Tuesday night into Wednesday, with additional rounds of showers possible through Christmas Day and into the weekend. Gusty winds and high rainfall rates could lead to localized flash flooding, especially in urban areas, along small streams and near recent burn scars.

With several systems expected to move through back-to-back, soils across many regions will become increasingly saturated, raising concerns about runoff, flooding and slope stability as the storm sequence continues.

“Tuesday through Saturday looks to be an extended period of significant rainfall,” the National Weather Service office in Los Angeles wrote. “By Saturday evening, rainfall totals will range 4–8 inches across coastal and valley areas to 8–12+ inches across the foothills and mountains.” Please take the necessary protective actions as flooding and debris flow will be a major issue this upcoming week.”

But when the rain finally stops, the risk isn’t necessarily over.

Expected impacts of atmospheric rivers in California

The National Weather Service office in Los Angeles and Oxnard is warning of a major storm with significant hydrologic impacts, driven by a strong system tapping into subtropical moisture. Rain is expected to begin Tuesday, with the most intense rainfall arriving Tuesday night into Wednesday as a powerful low-level jet enhances rain rates, particularly across the mountains of Santa Barbara, Ventura and Los Angeles counties.

Forecasters say there is a high chance of rainfall rates near or above 1 inch per hour in the mountains early Wednesday, with localized rates possibly reaching 1.5 inches per hour. Even lower elevations could see brief bursts of heavy rain as deep moisture reins in place.

Strong winds will add to the hazard with gusts of 40 to 60 mph expected across mountain areas — and isolated gusts up to 80 mph in favored locations. A High Wind Watch has been posted for portions of the Central Coast, Santa Barbara, Ventura and Los Angeles counties.

After a brief lull late Wednesday, another round of rain and wind is expected on Christmas Day. While rain rates may be lower overall, forecasters say the return of strong southerly flow could still produce short periods of heavier rain, further compounding flooding and debris-flow concerns.

By the time the storm sequence winds down this weekend, rainfall totals could reach 4 to 8 inches in coastal and valley areas and 8 to more than 12 inches in foothills and mountains, according to the National Weather Service.

How to prepare for an atmospheric river

The weather service in Portland said residents should take these steps to prepare for the heavy rain:

• Check your home’s gutters and clean them out if they are clogged with leaves from recent winds.
• Practice caution around low water crossings, where street drains may back up and cause rain to pool.
• Slow down while driving off interstate and bridge ramps and when making turns. Recent heat has caused oil in the road to come to the surface, making roads slick when rainfall is added.
• Expect creeks to rise and have more flow in the Coastal Range, Willapa Hills and Cascades.
• Check your local weather forecast for expected rainfall amounts and timing.

California weather watches and warnings

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