The sky will be primarily gloomy by Wednesday, but the temperature will be moderate and dry.
As a wet Pacific system passes across Southern California, the likelihood of rain will rise by Thursday, with rain becoming probable Thursday night into Friday.
A persistent trough off the coast of California will continue to feed chilly and unstable weather systems over the state over the holiday weekend and into next week, bringing spells of rain and snowfall in the mountains, gusty winds, and temperatures below average.
Overnight, areas of gusty N-NE winds were reported below the San Gorgonio and Cajon Passes. At the same time, moderate offshore sfc pressure gradients prevailed from the high deserts to coastal Southern California.
It was 10-15 degrees Fahrenheit warmer overnight, owing to widespread high clouds, higher dewpoints around the shore, and those sometimes forceful northeasterly breezes.
Even though the heavy clouds will continue to hang around for the next three days, modest offshore flow and a warmer air mass will maintain daytime temperatures around normal through tomorrow.
Looking forward to Wednesday, we should see a notable shift in our weather as the flat ridge located south of us moves eastward.
After picking up the remnants of a vast, wet low-pressure region over the East Pacific, this trough will begin to drag it towards the United States. Even though it will have lost most of its punch, it will still contain a significant amount of moisture.
This will be adequate to produce moderate quantities of rain throughout most of the state's terrain.
Because it is coming from the Pacific and minimal cold air incursion from the north, snow levels will be relatively high here, preventing any primary accumulation below 6500 FT from occurring until the weekend.