A powerful atmospheric river is poised to impact Northern California starting Monday, with the storm expected to reach Los Angeles County by Tuesday. This weather event brings renewed hope for Southern California as it may signal an end to a challenging fire weather season.
The atmospheric river is anticipated to be particularly strong in Northern California, where a flood watch is in effect from Monday afternoon until Wednesday morning. Heavy snowfall is also expected in the Sierra Nevada mountains, raising concerns about potential flooding and hazardous conditions.
In Los Angeles County, meteorologists have noted that what initially seemed to be a single storm system has now split into two distinct systems. The first storm is expected to bring rain from Tuesday through Friday, with the heaviest precipitation likely occurring between Tuesday night and Wednesday midday. Forecasts suggest that areas in L.A. County could receive between one-quarter to one inch of rain, with specific estimates including Covina at one-third of an inch, Long Beach at two-fifths, and downtown Los Angeles, Santa Clarita, and Redondo Beach seeing approximately half an inch.
Rose Schoenfeld, a meteorologist with the National Weather Service in Oxnard, highlighted the potential for mudslides and road erosion, especially in sensitive canyon areas. There is a 5% chance that rainfall rates could escalate enough over recently burned areas to trigger significant mudslides or debris flows. Winds are expected to accompany the rain, with gusts reaching 10 to 20 mph in populated areas and 20 to 40 mph in the mountains and deserts.
The second storm, a cold frontal system, is forecasted to arrive on Thursday and last into Friday. This system is expected to have a greater impact on Los Angeles County compared to the initial storm. Rainfall rates during this period could also reach up to half an inch per hour, raising further concerns about mudslides, particularly near areas affected by previous wildfires.
Northern California, which has already experienced an atmospheric river over the weekend, is bracing for a second round of rain. Cities like San Francisco could see between 3 to 4 inches of rain, while Santa Cruz may receive between 4 to 6 inches. Heavy snowfall in the Sierra Nevada could lead to near white-out conditions, with wind gusts reaching as high as 70 mph.
Overall, while Southern California anticipates light to moderate rainfall, the focus remains on the potential hazards posed by the storms, particularly in areas with recent burn scars. As the region prepares for these weather events, officials emphasize the importance of staying informed and prepared for rapidly changing conditions.