Another atmospheric river heads to SoCal; heavy rain expected

Southern California residents can expect a respite from recent mild weather as a potent pair of storms prepares to sweep the region, bringing significant rain and snowfall in their wake.

According to the National Weather Service, the first storm system, heralded by strong rains, is set to make landfall Wednesday night and peak during Thursday’s early hours, particularly around Los Angeles County.

A flood watch is in effect for counties across Riverside, San Bernardino and Orange, covering Thursday morning to Friday morning. The flood watch was in anticipation of “excessive runoff [that] may result in flooding of rivers, creeks, streams, and other low-lying and flood-prone locations,” according to the NWS.

The incoming storm system is also predicted to see snowfall extending across the San Gabriel Mountains and into mountain areas of Riverside and Ventura counties, amounting to as much as 24 inches of snow above 7,000 feet.

Winter storm warnings underscore the hazardous conditions expected to envelop the mountains, where considerable snow accumulation may lead to significant travel delays. For those planning mountain travel, authorities urged caution, recommending carrying winter emergency supplies. 

Preliminary weather patterns suggest a temporary clearing in Southern California skies, with sunshine likely on Friday and Saturday, but meteorologists caution that this break could be short-lived. Another storm, potentially more substantial, looms on the horizon with arrival times uncertain between Sunday and Tuesday.

Projections from the NWS hint at a span of 12 to 24 hours of relentless rain accompanied by robust winds. However, there is a possibility that the storm system may veer north, reducing the impact on Southern California. 

Prior to these developments, the Golden State enjoyed dry, warm weather, which is now giving way to a weather disruption expected to extend its effects beyond traditional rain showers. Residents, particularly in Orange County, are bracing for unwelcome flood watches coupled with high wind watches and advisories about high surf lasting from early Thursday through Saturday morning.

The NWS in Los Angeles foresees up to 2 inches of rain Wednesday through Thursday, with mountain regions anticipating five inches and wind gusts hitting 50 mph. The NWS’s Climate Prediction Center acknowledges over a 60% likelihood of heavy precipitation migrating toward southern California, heightening meteorologists’ concerns for harsh weather conditions in the coming days.

These atmospheric disturbances, often known as the Pineapple Express when originating from the subtropics, form when cold Arctic air converges with the warm, moist tropics, leading to heavy precipitation.

Reporting by KTLA, KNX News and Newsweek