Time-lapse storm images explain why the West Coast is getting pummeled with rain

The cause of storms that brought record rains to the West Coast for much of this week were captured in a time-lapse video compiled at NASA's Goddard Space Flight Center using data from NOAA's GOES-West satellite.

The video shows how over the course of four days, from Nov. 30 to Dec. 3, a low-pressure system several hundred miles west of California merged with a large stream of moisture that swept east toward the southern part of the state and Mexico. They converged on Dec. 1, bringing more rains to southern California on Dec. 3.

California has been hit by a prolonged drought that caused widespread water shortages and could end up costing cost the agriculture $1.5 billion in losses this year. The latest soaker was a welcome reprieve but water managers are not yet calling it a drought buster.

Bill Patzert, a climatologist at NASA's Jet Propulsion Laboratory, said the heavy rains should, however, tamp down "the prospect of extreme wildfires when the Santa Ana winds are expected to return shortly."

Patzert described the storm as a "pineapple express of tropical origin" that met up with a low-pressure system off the coast.

"It is warmer moisture - like a fire hose aimed at us from the south of Hawaii," Patzert said. "This is an event. It is not a pattern."

According to the National Weather Service office in Los Angeles, rainfall on Dec. 2 in downtown Los Angeles was 1.21 inches, setting a new record for that date. The previous record was 1.10 inches that fell in 1961. The Los Angeles International Airport recorded a record-breaking 1.12 inches of rainfall on Dec. 2, beating the 1966 record of 0.73 inches.