My rather extensive blog on the storms for California I posted yesterday still stands for rain and snow amounts as well as snow levels with just a few minor changes and additions. Here is the link to that blog.
The satellite picture shows the first storm with the main band of rain as of 2 p.m. PST getting ready to move ashore.
The band of rain moves west to east across California tonight into tomorrow morning with the heaviest rain in the northern half of the state.
The second storm is out around 150W and this will move east-southeast and intensify. This will bring in rain later Thursday night and Friday.
The second storm will aim its impressive dynamics at the southern third of California. All models are very impressive with a strong low- and middle-level southerly jet moving in Friday with speeds of 40 to 55 mph at 2,500 to 5,000 feet above sea level and in excess of 60 mph at 8,000 to 10,000 feet. In addition there will be copious amounts of water available as precipitable water levels rise to 1.4 to 1.6 inches ahead of the front.
Here are two charts showing winds from the GFS at 925 mb and then 850 mb.
This strong jet will help enhance rainfall, especially on south-facing mountain slopes from Santa Barbara County to Los Angeles and western San Bernardino counties.
It is because of these dynamics and available moisture that I think some of the south-facing slopes of the foothills and mountains could see higher rainfall than what even I had yesterday. I would expect to see some amounts in the 6- to 8-inch range Friday into Saturday in the mountains with 4 to 6 inches in the spots in the lower foothills. This would include the recent burn area around the San Gabriel Valley.
The strong just probably will also help to enhance strong surface winds that could exceed 60 mph at the top of the Grapevine and in the mountains with 20 to 35 mph winds along coastal areas.
One other item. Thunderstorms can accompany the front Friday and also be around Saturday with the upper-level low cruising in. Any thunderstorm can bring hail and damaging wind gusts. An isolated waterspout or tornado cannot be ruled out either.
As always, you can catch me on Twitter at @Kenwxman.
The amount of water in the snowpack in the Sierra is far below normal for even this time of year.
Flooding will be a given, most widespread in the northern half of the state.
This storm will endanger life and property both on the seas and over land in a large area.
A huge storm is expected it impact much of the Bering Sea beginning Friday night
This will be the first significant statewide rain and snow event of the season.