Approaching storm fronts bring rain, snow in the Sierra later this week

SAN FRANCISCO -- The storm door was slowly beginning to creep open as the first of three weather fronts approached the Bay Area Sunday, bringing with it frigid temperatures for the start of the week.

The dip in the temperatures will be particularly noticeable on Tuesday and Wednesday mornings.

"The cold front associated with the trough will bring a burst of cold  air bringing temperatures of mid 30s to low 40s along the coast and low 30s inland for Tuesday and Wednesday mornings," the National Weather Service said. "The low temps brings concern for areas of frost in the inland valleys, such as the North Bay valley and Southern Salinas valley."

As the first system moves through it will kick the storm door wide open. Rain in the Bay Area and snow in the Sierra will begin on Thursday.

"Upper level dynamics support potential for widespread precipitation, with the usual hot spots being Northern Sonoma county, the Santa Cruz mountains, and the Big Sur coast," the weather service predicted. "Current guidance is forecasting generally 0.5 to 1 inch of rainfall with higher amounts over terrain where upwards of 2 inches appear likely. "

Then a third system will make for a wet weekend.

"Another round of rainfall is anticipated for the weekend as another trough is predicted to drop out of the coastal Pacific Northwest along a similar path," the forecasters said.

In the Sierra, the stormy weather will drop a foot or more on the Tahoe ski resorts.

"The official forecast has a couple feet of snow in the high Sierra from Wednesday night through Friday night," weather service forecasters in Reno warned.