Simulation of storm off of California coast (earth.nullschool.net)

A vigorous storm system off of California’s Pacific coast is pumping streams of moisture inland, depositing welcome rain in the drought-afflicted state.

The San Francisco Bay area has received 1-1.5 inches of rain so far today.  Through 11 a.m. Pacific time, 1.28 inches had fallen downtown, making it the 5th wettest day there since  2009 – according to Jan Null, a consulting meteorologist based in San Francisco.  Additional rain is likely this afternoon with daily amounts nearing 1.5 inches, which would make it the rainiest day since February 15, 2009.


Satellite water vapor image show large swirl off California moist transporting moist air (green) inland (NASA)

The rain is helpful, but substantially more is needed to ease the drought. “The 3-season deficit for San Francisco at the beginning of the rainfall season was 26.07 inches,” writes Null. “If you add that to the 23.65 inches needed for this season to ultimately reach normal we would need 49.73 inches to be at ‘normal’.”

Around Los Angeles, 0.25-0.5 inches of rain has fallen thus far today, though parts of southern California have received substantially more, where it hasn’t necessarily been entirely beneficial.

“The season’s biggest rainstorm is lashing Southern California, bringing down power lines, flooding residential streets and closing park trails,” reports the LA Times.


Storm summary graphic from National Weather Service forecast office in Los Angeles

Here’s some video of a mudslide in Camarillo Springs in southern California:

Rain is expected across California through Wednesday, with several inches forecast in many coastal areas as well in the mountains.


Rainfall forecast through Wednesday in California (National Weather Service via WeatherBell.com)

At high altitudes, the rain turns to snow with 1 to 2 feet predicted in Lake Tahoe above 7,000 feet.

Although rains from the current storm are predicted to taper off Wednesday, on the very positive side – long-range forecasts hint at a wet pattern for the Golden State for much of December and, perhaps, longer.


December precipitation outlook for U.S. favors above normal precipitation in California (National Weather Service)