The storm system will come in on Thursday and Friday. So far on the TWS' Southern California Weather Authority site there is a Special Weather Statement and Santa Ana Wind Watch.
NOAA's models bring a drier solution to the area, but I cannot let go of the tracking method I use for long range just yet. Until this goes too far east then this storm is still very much in play for Southern California.
Factors with system will go as followed ...
Track 1 - 2004 type pattern in-which strong upper level vorticity and temperature advection produced rapid convection and thunderstorms across the Southern California area, excluding Ventura County and points north and west of there. This was combined with a Santa Ana Wind event in-which thunderstorms + santa ana winds and low snow levels hit the southland. This is a rare but very powerful scenario.
Track 2 - The storm takes on a 2005-6 pattern in-which the center of the dynamics missed to the east, over Desert Center (Riverside County Deserts) and gave the area light snow and isolated thunderstorms.
Track 3 - Hits the California and Arizona border, misses the Southland and only gives a very strong Santa Ana Wind Event.
All scenarios are possible, but the track I see is very close to either Track 1 and if there was an in-between 1 and 2. Regardless, this is enough to warrant snowfall in the forecast at 3,000 feet and possibly low, powerful santa ana winds, thunderstorms, and much cooler temperatures regionwide.