Rain and mountain snow forecast through Christmas for Southern California
Two cold Pacific storm systems will bring rain and snow to Southern California for most of the week, including Christmas on Wednesday, and winter weather advisories for snowfall Monday could affect local mountain highways, the National Weather Service said.
The first storm was expected to arrive in the region late Sunday, have most of its impact on Monday, and then recede. The second front arrives on Christmas and will last through most of Thursday. And showers are expected between the two fronts, the NWS said.
The advisory for Los Angeles County mountains, excluding the Santa Monica range, will last until 10 p.m. Monday with snow accumulations of 6 to 12 inches above 7,000 feet, and 2 to 6 inches for mountain elevations below that.
For San Bernardino County mountains, the winter weather advisory will last until 4 a.m. Tuesday. Snow amounts for San Bernardino County mountains, which include several ski resorts, are forecast at 4 to 8 inches between 6,000 and 7,000 feet, and 8 to 12 inches above 7,000 feet.
No advisory was issued Sunday for mountains in Riverside County.
Low and high forecast temperatures for select cities Monday include 52 and 60 for Los Angeles; 48 and 59 for Long Beach; 48 and 56 for Pasadena; 53 and 60 for Newport Beach; 51 and 60 for Anaheim; 47 and 57 for San Bernardino; and 48 and 57 for Riverside.
What WILL be more impactful, however, is the snow.
Several inches likely on Mon in the San Bernardino Mtns, mostly above 5000-5500 FT.
Heavier snow arrives Christmas evening and into Thu. Dangerous travel conditions are expected in the mountains. Be prepared.
#cawx https://t.co/iIGNnSF7N1
— NWS San Diego (@NWSSanDiego) December 22, 2019
The second storm arriving on Christmas will be colder and the snow level could drop low enough to affect travel on the 15 Freeway in the Cajon Pass, the weather service’s San Diego office said.
At the Los Angeles-Kern County line where the 5 Freeway heads through the Tejon Pass, the Christmas storm was also expected to drop snow down to mountain-pass levels.
But “balancing this out is the fact the snow amounts near the Kern County line do not look like they will be too great,” the Los Angeles/Oxnard NWS office said Sunday. It said motorists should still check on mountain pass conditions, especially for Christmas night travel.
Peak rainfall from the first storm did not look significant in the Sunday forecasts — rainfall rates in the Los Angeles, Inland and Orange County areas were generally forecast to be at or less half an inch per hour.
There could be more intense rainfall in coastal Orange County and coastal-facing mountain slopes, and possible thunderstorms could also increase amounts.
We have a wet and snowy holiday week in store for #SoCal. Look for wet weather Sun-Mon and again Wed-Fri, with mountain snow. Stay tuned for details on when snow will affect mountain passes! #CAwx #LArain #LAsnow pic.twitter.com/g7gvFqKtzz
— NWS Los Angeles (@NWSLosAngeles) December 22, 2019
No flood advisories or warnings were issued Sunday, but there could be some urban flooding, the NWS said.
The Christmas day storm was forecast to move on by Thursday night, with clearing skies and warmer temperatures throughout the area.