California Weather Atmospheric River Flood the State as 'Pineapple Express' Hits

The first of intense California weather atmospheric river is drenching the Golden State with heavy rainfall and much-needed snow, causing flooding, travel hazards, and damage.

An atmospheric river is a long plume of Pacific moisture fueled by cold fronts that interact with California's mountainous terrain to produce extreme precipitation.

When Did the First Atmospheric River Hit?

The initial atmospheric river made landfall on Wednesday, halting cable car service as a San Francisco storm brought relentless rain.

On Thursday it shifted south, snarling the morning commute in Los Angeles and San Diego with downpours. The deluge comes ahead of an even stronger "Pineapple Express" weather system forecasted to arrive Saturday and pummel parts of California for over 24 hours.