A tropical moisture plume over the Pacific is forecast to feed two waves of precipitation and gusty winds as they move through Northern California through Monday.
The first wave of energy will push southward through Northern California today through Saturday.
The National Weather Service has issued a Winter Storm Warning for the Sierra Nevada above 8000 feet, which is in effect from 4 pm this afternoon to 4 pm Saturday.
Snow levels will start and remain high, generally above 7000 feet but some stronger convection this afternoon could bring snow levels a bit lower.
Snow accumulations of twelve to thirty inches are expected above 8000 feet.
The heaviest snow is expected late Friday night into Saturday morning. Snow will diminish
during the day Saturday.
Additionally, a Wind Advisory has been issued for both the Sierra Nevada and the Central Valley from 10 am this morning to 7 am Saturday.
Winds of fifteen to twenty-five mph are likely with gusts up to forty-five mph in the valley. Winds over the Sierra Nevada are expected from twenty to forty-five mph with gusts up to seventy-five mph.
The strongest winds are anticipated to occur this afternoon through the evening hours.
Precipitation amounts in the Central Valley through Saturday are expected to range around an inch.
This will be followed by another round of steady precipitation Sunday into Monday.
Through Monday, rainfall amounts for most of the Central Valley are expected to measure from two to five inches and five to ten inches are expected across the foothills and the Sierra Nevada.
Some of the impacts could include urban and small stream flooding and the potential for debris flows near wildfire burn scars. Also there may be localized power outages and downed trees due to breezy winds.