Introduction to the Storm
A powerful atmospheric river headed for Southern California is expected to drop several inches of rainfall, creating the potential for travel challenges primarily on Christmas Eve extending into Christmas, forecasters said Monday, Dec. 22.
The storm is due to arrive during the day Tuesday and will gradually intensify, bringing the heaviest rainfall from Tuesday night into Wednesday, forecasters with the National Weather Service said. A flood watch is to be in effect from 4 p.m. Tuesday to 10 p.m. Wednesday.
Expected Rainfall
“This will be the first heavy pulse of the atmospheric river,” said Rich Thompson, a meteorologist with NWS’ Oxnard office.
Los Angeles County valleys and coastal areas could see 4 to 8 inches through Saturday, Thompson said.
Residents in valley and coastal areas in Orange County and the Inland Empire could see upwards of 4 inches by the end of Wednesday, said Lauren Villafane, a meteorologist with NWS’ San Diego office.
The LA County mountains are expected to see between 6 and 12 inches of rainfall, while mountain ranges in Orange County and the Inland Empire could see 5 to 9 inches during the same period, forecasters said.
Preparations and Concerns
Snow is not likely to fall below 7,500 feet until the weekend, they said, because of a warm air mass and subtropical moisture associated with the atmospheric river, Thompson said. Over the weekend, snow levels may be seen at elevations of 7,000 feet and above.
But the primary concern for forecasters is Christmas Eve, when heavy rainfall could bring mudslides and debris flows to burn scar areas and the possibility of urban flooding, Thompson said.
“The LA River won’t be overflowing, but there will be significant flow, so there could be swift water rescue issues there,” Thompson said. “Pretty much anything you can imagine with bad water things are definitely possible with this storm.”
Forecasters recommend keeping an eye out for road closures and preparing for additional travel time. Do not attempt to cross flooded roadways, they warn.
Emergency Preparations
Los Angeles’ Emergency Operations Center was activated Monday to coordinate preparedness measures for the upcoming storm, city officials said, with resources strategically deployed to assist with swift water rescues, mud and debris flows and other rain-related issues “with a specific focus in burn scar areas.”
The Los Angeles Homeless Services Authority on Monday began conducting outreach to inform the population of the weather and provide them with safety information and supplies, officials said.
In Pasadena, where some residents’ homes are near Eaton fire burn scars, sandbags were available at Pasadena Fire Department Station 37, 3430 E. Foothill Blvd., and Station 38, 1150 Linda Vista Ave., from 8 a.m. to 5 p.m., officials said.
Residents were urged to consider installing protective barriers to keep water and debris away from structures and to clear debris from gutters and downspouts to improve water flow. Residents were also urged to prepare emergency go bags in the event of an evacuation warning or order.
Conclusion
The upcoming storm is expected to bring significant rainfall to Southern California, with the potential for travel challenges, mudslides, and debris flows. Residents are urged to prepare for the storm by keeping an eye out for road closures, preparing for additional travel time, and not attempting to cross flooded roadways. Emergency preparations are underway, with resources deployed to assist with swift water rescues, mud and debris flows, and other rain-related issues.
FAQs
Q: When is the storm expected to arrive?
A: The storm is due to arrive during the day Tuesday and will gradually intensify, bringing the heaviest rainfall from Tuesday night into Wednesday.
Q: How much rainfall is expected?
A: Los Angeles County valleys and coastal areas could see 4 to 8 inches through Saturday, while the LA County mountains are expected to see between 6 and 12 inches of rainfall.
Q: What are the primary concerns for forecasters?
A: The primary concerns are Christmas Eve, when heavy rainfall could bring mudslides and debris flows to burn scar areas and the possibility of urban flooding.
Q: What should residents do to prepare?
A: Residents should keep an eye out for road closures, prepare for additional travel time, and not attempt to cross flooded roadways. They should also consider installing protective barriers to keep water and debris away from structures and clear debris from gutters and downspouts to improve water flow.
