Breezy southerly winds and isolated showers north of I-80 are expected into the evening. More appreciable precipitation chances then arrive Sunday through Tuesday as a couple of weak waves impact the region. Mild and dry weather with gusty north to east winds are then expected for the latter part of week period.
Discussion
Weak system moving through the region today has been bringing light amounts of showers to the interior, mostly over the mountains. No impacts to travel are expected with this first wave that will be dissipating as we go through the evening. Another weak but slightly stronger system moves into the region late Sunday and Sunday night with the heaviest precipitation expected Sunday night for the western slopes.
Minor to moderate impacts to travel look possible at this time during that time period over the passes with along I-80 expected to receive the greatest amount at around 5 inches of snow.
Breezy conditions will be associated with the system as it passes through the valley with up to 45 mph near the crest. The strongest valley winds are expected north of Oroville Sunday afternoon as the front approaches. Precipitation amounts for the mountains will range from around a quarter of an inch or less for the mountains of Tuolumne County to around an inch for western Plumas County to 1.25 inches for western Shasta County.
There looks to be a little bit of a break on Monday between systems with a slightly stronger system than the previous one expected later in the day. This system will mainly arrive Monday night but a few showers between systems are possible, especially over the mountains. This one while not strong may bring some moderate impacts to mountain travel. Light amounts of precipitation for the valley with generally under a quarter inch expected.
The mountains will range from around a third of an inch for the mountains of Tuolumne County to around an inch for western Plumas County to 1.5 inches for western Shasta County. Heaviest snow accumulations will be above 4500 to 5000 feet but some local snow levels down to near 3500 feet are possible over Shasta County.
Breezy conditions but a little stronger will also be associated with the system as it passes through the valley with up to 40 mph near the crest. The strongest valley winds are expected north of Sacramento.
Extended Discussion (Wednesday through Saturday)
The low pressure area from the day before will be moving southeast of the area on Wednesday into Arizona and high pressure will begin to build along the coast. North to northeast winds will be setting up over the region Wednesday and Thursday.
Current timing of winds has northerly winds in the valley for the daytime but strengthening in the evening for the westside of the valley and coastal mountains. Gusty easterly winds for the Western slopes increase late in the evening through Thursday morning.
The winds look like they peak Wednesday night and Thursday morning. Continued north to east winds will continue into the weekend Friday but not as strong and gradually weakening a each day. NBM Model is indicating a 40-80 percent probability of wind gusts of 40 mph or greater over the westside of the valley Thursday morning.
Probability of northeast wind gusts greater than 40 mph over the coastal and Sierra Nevada at 40-90 percent.
Mainly clear skies and warmer temperatures throughout the extended period with temperatures warming into the 70s for the valley Thursday through Saturday.