NWS Hanford has released this statement:
MODELS HAVE COME INTO STRONG AGREEMENT REGARDING THE EVOLUTION OF A STRONG WINTER STORM OVER THE UPCOMING WEEKEND. WHILE THERE
CONTINUES TO BE SOME MINOR TIMING DIFFERENCES, IT IS CLEAR THAT
THERE WILL BE A THREAT OF VERY HEAVY SNOW IN THE SOUTHERN SIERRA. IN AGREEMENT WITH NWS SACRAMENTO AND RENO, WE HAVE UPGRADED THE WINTER STORM WATCH TO A WARNING. HAVE ALSO EXTENDED THE WARNING THROUGH SUNDAY NIGHT. WHILE THE FIRST WAVE OF PRECIPITATION WILL HAVE THE POTENTIAL TO BE PLENTY STRONG IN THE SOUTHERN SIERRA…THE SECONDARY TROUGH COMES IN NEGATIVELY TILTED LATE SUNDAY AND LOOKS TO BRING A SHORT BUT INTENSE PERIOD OF PRECIPITATION WITH A SIGNIFICANT ASSOCIATED MOISTURE FETCH.
WINDS WILL BECOME GUSTY ON SATURDAY IN THE VALLEY AND A WIND ADVISORY MAY BE NEEDED…ESPECIALLY ALONG THE I-5 CORRIDOR. WINDS WILL PICK UP IN THE KERN COUNTY MOUNTAINS AND DESERT SUNDAY NIGHT AND INTO MONDAY AS THE TROUGH FINALLY PUSHES THROUGH.
On the Coast, John Lindsey reports rain likely from Friday thru Monday in the SLO area.
Here is his report showing a series of storms lining up:
A vigorous weather system is now crossing into far Northern
California this morning with 50+ mph southerly winds and periods
of heavy rain.
This cold front will decrease in intensity and continue to move
southeastward towards the Central Coast. This cold front will
produce increasing clouds, southerly winds and warmer overnight
low temperatures by Friday morning. Scattered rain showers are
forecast to start on Friday evening as the cold front approaches
San Luis Obispo County. Rain showers will turn to study rain
Friday night into Saturday morning with the frontal passage.
A 1,005 millibar low pressure system will follow the cold front
on Saturday afternoon and produce strong to gale force (24- to 38-
mph) southwesterly winds and rain showers. The southwesterly
winds will decrease and shift out of the west and the rain
showers will end by Saturday night. Heavy Sierra snow will
develop on Friday and continue through Saturday. Snow levels
will begin low tonight and will gradually rise to about 3,000
and 5,000 feet north to south by Saturday.
Another weather system will cross San Luis Obispo County on
Sunday afternoon into early Monday morning with potentially
heavy rain and gusty southerly winds.
Dry weather will return Christmas Day. However, another
low-pressure system may produce increasing southerly winds
and moderate to heavy rain on Wednesday afternoon into next
Thursday morning. At this time, unsettled weather is forecast
to continue into next weekend.