The start to December has been quiet across Northern California with no rain in the forecast since late November. But, the dry streak is about to come to an end as the storm door reopens allowing for multiple storm systems to move in this week.
Tuesday and Wednesday will stay mainly dry and sunny. Clouds increase Wednesday afternoon as the first storm system moves in by Wednesday night.
Two storm systems will impact the region mid-week through the weekend with more rain and Sierra snow chances. By early next week, we are watching the potential of a third storm moving in on Monday.
Over the last week, most of California has sat underneath a large ridge of high pressure. This has blocked any incoming storm systems, kept the region dry, and pointed the storm track to the north.
By Wednesday, high pressure begins to break down allowing our next storm system to move in.
This area of low pressure will be weak and fast-moving but it will be just enough to open the storm door open and keep active weather around over the next few days.
This fast-moving storm system will arrive during the day on Wednesday, impacting the Coastal Range, Bay Area, and Northern Sacramento Valley before arriving to the greater Sacramento area by 9 p.m.
Rain begins to fill in across the Valley and snow across the Sierra, Wednesday night through Thursday morning. We are expecting our heaviest precipitation while many are sleeping.
By Thursday morning's commute, scattered showers continue across the valley and foothills as the storm continues to move east. Expect a mostly dry afternoon and evening across the valley as the storm moves out.
Snow begins across the Sierra around 4,000-5,000 feet in elevation. Snow levels will drop quickly as the storm begins. We are expecting 2-6'' of snow for elevations above 5,000 feet. Chain controls will be possible, especially on Thursday morning. Light snow showers will linger into early Friday before clearing.
With the fast nature of this storm, we're only expecting 0.10-0.50'' in the Valley and up to one inch of rain in the foothills.
There will be a brief break in activity from Thursday afternoon through Friday afternoon before our second storm moves in.
The wettest of the two storm systems this week arrives on Friday. The day will start mainly dry as clouds begin to rebuild.
Scattered showers return to the Northern Sacramento Valley through the morning before the main event arrives.
Timing has been back and forth between models of starting earlier and later in the day on Friday. Right now, we can expect scattered showers through the late afternoon and evening on Friday.
Snow will begin across the Sierra just after 9 AM starting along and north of I-80 first, before moving south.
This storm will have the potential to interrupt weekend travel plans with slick roads in the valley and chain controls over the Sierra expected.
Snow levels will rise as this storm moves in, but stay between 4,500 -6,000 feet in elevation through Friday and Saturday. Colder air moves in with the front Saturday night, dropping snow levels to the 4,500 range.
Our heaviest precipitation arrives Friday night through Saturday afternoon. A good-soaking rain in the valley and foothills will be possible. The highest rain totals will be north of I-80, with lighter amounts closer to Stanislaus County.
If you had outdoor plans on Saturday, finding an indoor solution will be best as rain continues through Saturday into Sunday morning.
Showers begin to taper off by Sunday morning, leaving Sunday afternoon dry across the valley and most foothill locations. A few lingering snow showers will be possible across the Sierra after sunrise.
The remainder of the weekend stays mainly dry before we're eyeing another quick storm system by Monday.
Rain and snow amounts will fluctuate with the timing and track of each storm this week. But adding up totals this week, these next two storm systems will help keep us on track to hitting our snowpack and water goals by next year.
Over the next five days, we are expecting our highest rain and snow totals along and north of I-80.
We could see some spots in the Northern Sacramento Valley reach 1.5-2'' of rain, whereas closer to Downtown Sacramento up to 1 inch of rain is expected.
Amounts vary across the foothills as some areas north of I-80 will have the chance of seeing 2-3'' of precipitation, with up to 1.5'' of precipitation across central foothill spots.
Snow totals may also change as storms move in, based on changing snow levels.
By Sunday, expect 8-16'' of snow across elevations above 5,000 feet. We could see up to two feet of snow across mountain peaks by Sunday. Periods of moderate to heavy snowfall are expected Friday through Saturday.
Be prepared for winter travel if your weekend plans take you over Sierra passes. Chain controls, delays, and closures are possible.
One more storm system looks to slide in as we start next week. Early models show this moving in as early as Monday morning. Producing more scattered rain showers and more snow across the Sierra through Monday night.
This storm will be weak and fast-moving similar to our storm on Wednesday. We are expected to dry out by Tuesday with partly cloudy skies through the afternoon.
After Monday, our pattern dries out again through mid-week, but another storm or two could be possible toward the weekend.
Monday's storm timing and amounts are expected to change over the next few days so make sure to stay with the CBS Sacramento First Alert Weather team as we iron out the details.