...Colder Pacific storm tonight into early Saturday...
* impacts: chain requirements possible with accumulating snow over trans-Sierra mountain passes tonight through early Saturday. Potential thunderstorms Friday with heavy rain, small hail, and gusty wind.
* Confidence: high in timing. Medium in precipitation amounts and thunderstorm potential.
* Timing: precipitation then increases and spreads over all of interior northern California this evening into Friday. Best thunderstorm chances are Friday into Friday evening over the southern Sacramento and northern San Joaquin valleys.
* Snow levels: initially around 6000 to 7000 feet today into tonight...lowering to around 4500 feet by early Saturday.
* Precipitation amounts: generally around half an inch or less in the Central Valley with higher amounts possible in the foothills and mountains and with thunderstorms. Snow amounts from 5 to 10 inches over the higher mountain terrain.