The reason the snow hasn't melted more already is the temperatures have been 10 to 20 degrees Fahrenheit blow normal since Christmas of before

This is something that needs to be considered too. As the East Coast breaks heat records right and left for some reason this has been likely the coldest year I can remember for almost 30 years here in Northern California.

For example, our temperatures SHOULD BE in the 70s or up to 80 along the coast as long as we aren't having too much fog (high or low). If the sun is out like it's been the last week or two it should be warmer than the 55 degrees Fahrenheit it has been.

Also, most years since 2000 the water should be now between 54 and 57 degrees at it's lowest. 

But, instead the water in the ocean is 50 to 53 degrees Fahrenheit which is very unusual (at least since 2000) this is true. So, all these factors contribute to the snow not melting very much yet.

But, all you need is one heat wave to flood the entire Sacramento Valley and San Joaquin Valleys which are the same valley actually just one is north of Stockton and one is south of Stockton basically. It appears where the Sacramento River heads for San Francisco is where the demarcation seems to somewhat be.