The current El Nino system -- a natural warming of the central and eastern Pacific Ocean that interacts with the atmosphere and changes weather worldwide -- has tied a system in 1997-1998 as the strongest on record.
The week's most powerful storm came and went on Wednesday, Jan. 13 after it flooded roadways and stranded motorists across greater Los Angeles. Well over 2 in of rain fell on several mountain areas, including 3.5 in at the San Gabriel Dam in the Angeles National Forest.
The risk of flooding south of the dam would exist if the San Gabriel Mountains are soaked with a series of unrelenting storms from El Nino, sending large amounts of mud, rocks and burned trees into an already full Hahamongna basin, according to Los Angeles County dam safety officials.
The tail-end of a series of several El Nino-driven storms brought scattered showers and isolated thunderstorms to Southern California on Thursday, Jan. 14 along with pounding surf and serious winds.
El Nino-fueled storms also brought heavy snow to northern Arizona where Grand Canyon National Park halted all shuttle bus service. Park officials said Thursday morning that South Rim roads are snow-packed and icy.
The National Weather Service issued a winter storm warning for much of northern Arizona through midday Friday due to heavy snowfall -- as much as an inch an hour. Flagstaff had 19 in of snow on the ground as of Jan. 14.
Forecasters predicted significantly less rain than has pelted the state since Jan. 10, but warned that flash flooding was still possible before the skies finally clear.
Ski areas celebrated a week's worth of snow, but motorists heading up the mountains were warned of icy conditions above 4,000 ft. Big Bear resort east of Los Angeles hailed more than a foot of new snow.
Damaging surf was possible from Ventura County south to Orange County, with waves topping 10 ft. In Los Angeles County's Redondo Beach waves overtopped the breakwater and caused minor flooding in low-lying areas.
Voluntary evacuation advisories in some burn areas in danger of mudslides were cancelled. But authorities evacuated 10 mobile homes in the Newhall area northwest of Los Angeles as watery mud flowed into the streets from hillsides burned bare in a June fire, Los Angeles County officials said. No injuries or serious damage were reported and residents were expected to be able to return Thursday.
In San Diego County, winds were serious enough to bring a brief tornado warning Wednesday.