Introduction to the Storm
Several days of rain and powerful wind gusts are in the forecast this week as a winter storm settles into Southern California for the holiday. The Christmas week storm is expected to deliver light rain Tuesday evening before reaching its peak on Wednesday. Another wave of rain is in the Christmas Day outlook, increasing the risk of debris flows in recent wildfire burn zones.
What to Expect
"We are tapping into some tropical moisture, and atmospheric river," said NBC4 meteorologist Belen De Leon. "We have pretty much a firehose that is aimed toward California." Atmospheric rivers and long plumes of moisture in the sky over the Pacific Ocean have fueled some of California’s historic winter storms, which draw moisture from atmospheric rivers as they move toward California.
Key Points to Know
What to Know
- Rain will start Tuesday night and reach its peak Wednesday before another wave of rain on Christmas Day.
- Strong winds with gusts up to 70 and 80 mph are in the forecast as the multi-day storm settles in for the holiday.
- Evacuation warnings were issued for area burn scars, including residences near the Palisades and Eaton fire zones.
- A flash flood watch will be in effect through Thursday evening for much of Southern California.
- Rain is expected to continue into Saturday.
- Rainfall estimates are 3 to 6 inches of rain for most areas with Ventura and Los Angeles counties on the high end of that range. Some mountain and foothill communities might see 5 to 10 inches.
The Storm Timeline
In addition to days of rain expected to continue into the weekend, strong winds, including gusts up to 80 mph in the mountains, will raise the threat of toppled trees and other damage. Here’s the holiday storm timeline:
Tuesday: Mostly Dry with Clouds, then Evening Showers
Clouds blanketed Southern California early Tuesday, but most of the day will be dry until scattered showers develop around 7 or 8 p.m. High wind warnings and wind advisories go into effect at midday and continue through Thursday afternoon. Moderate to heavy rain develops around 11 p.m. in Los Angeles and Ventura counties, setting the stage for the overnight. Sustained winds of 30 to 50 mph are possible with potentially damaging gusts of 70 to 80 mph in the mountains and foothills. Strong winds coupled with soaked soil increase the risk for downed trees.
Homes in Pacific Palisades at risk of being affected by potential mudslides have been given evacuation warnings as the storm makes its way to the region.
Wednesday: Heavy Overnight Rain and the Peak of the Storm
The multi-day storm will reach its height on Wednesday when moderate to heavy overnight rain moves from west to east. Thunderstorms are possible with rainfall rates of 1 inch per hour at times.
Here’s when to expect the rain and where:
- Ventura County: Midnight to 7 a.m.
- Los Angeles County: Midnight to 4 p.m.
- Orange County and Inland Empire: 3 a.m. to 8 p.m.
By late Wednesday morning, rainfall intensity will scale back, but the storm will still produce pockets of moderate to heavy rainfall. Around 3 p.m., calmer conditions are in the forecast for Ventura and LA counties before more rain Wednesday night.
Those who live in burn scar areas in Altadena are under evacuation warnings.
Thursday: Soggy Christmas Day
Christmas Day starts with scattered showers, but there will be breaks in the rain. Around midday, a line of heavy rain will move from west to east before widespread rain as a flood watch continues into the evening. This wave of the storm will likely move through more quickly than the first, pushing into Ventura County around noon, LA County around 2 p.m. to 3 p.m., and Orange County and the Inland Empire around 7 p.m. or 8 p.m.
Rainfall estimates are 3 to 6 inches of rain for most areas with Ventura and Los Angeles counties on the high end of that range. The persistent rainfall forecast led to evacuation warnings that go into effect Tuesday for recent burn scar areas, including residences near the January Eaton and Palisades fires in Altadena and the Palisades. The warnings urge residents to prepare for possible evacuation orders due to the threat of debris flows.
Conclusion
The storm is expected to bring significant rain and strong winds to Southern California, with the peak of the storm on Wednesday. Residents are advised to prepare for possible evacuation orders and to stay safe during the holiday season. Not much snow is expected from the storm, but some resorts could see a fresh layer by the weekend.
FAQs
Q: When will the rain start?
A: The rain will start Tuesday night and reach its peak on Wednesday.
Q: How strong will the winds be?
A: Strong winds with gusts up to 70 and 80 mph are in the forecast.
Q: Are there any evacuation warnings?
A: Yes, evacuation warnings were issued for area burn scars, including residences near the Palisades and Eaton fire zones.
Q: How much rain is expected?
A: Rainfall estimates are 3 to 6 inches of rain for most areas with Ventura and Los Angeles counties on the high end of that range.
Q: Will it snow?
A: Not much snow is expected from the storm, but some resorts could see a fresh layer by the weekend.
