Coastal Rain, Mountain Snow Headed For California Tonight

By Brian Edwards, Meteorologist

January 5,2013; 4:08PM,EST

A potent disturbance will dive through California tonight into Sunday, bringing rain to the coast and the valleys while snow accumulates in the mountains and on the Grapevine.
Rain will develop from San Francisco through Crescent City, California late this afternoon and continue into tonight. Most coastal areas are expected to pick up a quick quarter to half inch of rain, which isn't a terribly large amount of rain for this time of year.
Rain will spread farther south tonight into central California, with snow developing in the higher elevations of the Sierra Nevada Range.
The real trouble will occur across central and southern California as the disturbance drags a pool of cold air inland. This pool of cold air will cause snow levels to drop to between 3,000 and 3,500 feet in the Sierra Nevada Range. Snow accumulations on the order of 3 to 6 inches are expected through the day on Sunday.
Travel could become difficult along Interstate 80 through Donner Pass late tonight into Sunday as the snow comes down hard for a few hours.
Rain and snow will develop farther south throughout Southern California Sunday morning, bringing a little rain to Los Angeles and San Diego. Rainfall totals across this region will average around one-quarter of an inch, which could lead to some slow travel along the Interstates.

Snow will fall in the mountains of Los Angeles and Ventura counties with snow levels dropping to about 4,000 feet by Sunday.
This could cause dangerous travel conditions to develop along the Grapevine (Interstate 5) by late-morning Sunday.
Snow accumulations above 4,000 feet in these Southern California mountains are expected to average 1-3 inches with the potential for 6 inches above 5,000 feet.
In addition, gusty winds will howl out of the northwest later in the day Sunday throughout the Interstate 5 corridor and below passes and canyons. Wind gusts to 40-50 mph are possible and could create additional travel nightmares into Sunday night.
This disturbance should finally shift south and east of California by Monday morning with much drier weather moving into the state behind it.
Another bout of stormy weather and a surge of cooler temperatures is likely toward the end of next week. Keep checking back with AccuWeather.com over the next few days for more information on potential travel delays across central and southern California.