Southern California is facing flooding rain, isolated severe thunderstorms and low-elevation snow to end the weekend, which is common in a strong El Niño weather pattern.
A storm will strengthen as it moves over Southern California and sweep across the interior Southwest into Sunday night.
"While a blockbuster storm is not likely, enough rain will fall to cause minor flash and urban flooding issues and trigger a few mudslides in recent burn areas," AccuWeather Senior Meteorologist Alex Sosnowski said.
Motorists should be prepared for slick conditions due to the rainy travel. Disruptions to outdoor activities are likely from San Diego to Los Angeles as well as much of the Inland Empire.
Rainfall between 0.50 of an inch to 1 inch are likely from Los Angeles to San Diego. However, the west- and southwest-facing mountainsides of Southern California may receive 1-3 inches of rain from the storm on Sunday.
Enough rain and wind can occur along with poor visibility to lead to airline delays at Los Angeles and San Diego.
"In addition to localized flash flooding and mudslides, there is concern for a few thunderstorms with damaging winds on Sunday in Southern California," AccuWeather Meteorologist Dave Samuhel said. "There can even be an isolated tornado."
High winds will keep the waves high off the California coast into Monday.
This storm system will pull chillier air across the region. Temperatures will dip below average from Sunday into early February. Precipitation over the mountains and passes will transition from rain to snow.
"Snow levels will fall as low as 2,000 feet near Tejon Pass to 3,000 feet in the mountains east of San Diego," AccuWeather Senior Meteorologist Kristina Pydynowski said. "There could be a light coating in these lowest elevations with more substantial snow in the higher elevations."
"Up to a foot of snow is likely at elevations above 7,000 feet," AccuWeather Senior Meteorologist Ken Clark said.
Significant travel problems will develop in the mountains, as well as some passes, as the snow clogs the roads. Winds will further create hazardous travel by severely blowing and drifting the snow around.
"Travel will become extremely treacherous through Tejon Pass Sunday afternoon night as 4-8 inches of snow will fall with strong winds creating blizzard conditions," Samuhel said.
Less snow is expected for Cajon Pass on Sunday night, but there could still be a coating that could lead to slick spots.
Temperatures will be low enough for snow to develop in the mountains outside of Las Vegas, Utah, the Colorado Rockies and the Highlands of central Arizona. Over a foot of snow may fall in the Rockies and southern Wasatch.
After four inches of snow fell from Saturday into Saturday night, Salt Lake City could get another coating of snow from this storm on Sunday night.
Gusty winds will accompany this storm from Southern California to New Mexico. Winds could occasionally gust over 50 mph over the ridges, through the passes and in the open desert areas.
Those traveling along interstates 8, 10, 17, 25 and 40 will need to have a firm grip on the steering wheel when traveling into Monday morning.
Much of California will dry out on Monday as snow will continue to fall across the Four Corners region.
This storm will track across the Four Corners through Monday before reaching the central Plains into Tuesday, bringing severe weather and a blizzard to the central United States.
There will not be a threat of any additional storms this week as a large area of high pressure will bring a stretch of drier weather across the Southwest.
"In the wake of this storm, the storm track will pull northward again next week and may stay there through at least mid-February," Sosnowski said.
So far this winter, rainfall across much California has not been typical of a strong El Niño pattern.
Clark noted in his blog that rainfall during the current El Niño is well behind the pace of the 1997-98 El Niño.
However, there are still two to three months of winter left for significant storms to impact the Southwest.