January 14, 2019 – A few showers will be possible to the south and west of Sacramento by later today. Precipitation is then expected to spread northward across the region tonight and Tuesday as the next system approaches. Breezy southerly winds are expected Tuesday. A stronger Pacific storm will move through NorCal later Wednesday into Thursday with heavy precipitation and strong winds. Drier weather expected by the weekend.
Discussion
Satellite imagery shows some clouds beginning to spread northward across interior NorCal ahead of the low off the central California coast while radar indicates a few showers well to our southwest.
Patches of fog have developed across portions of the Central Valley from Sacramento southward and will linger this morning. Current temperatures range from the teens to lower 20s in the mountain valleys to the mid 30s to mid 40s elsewhere.
Dry weather is expected to continue across most of interior NorCal today. Generally light precipitation will then spread northward across the region tonight and Tuesday as of the offshore low moves north. Southerly winds are expected to begin increasing across the southern half of the forecast area by Tuesday afternoon as surface pressure gradients tighten ahead of the next system.
That system will move in Tuesday night into Wednesday bringing moderate amounts of snow to the mountains along with rising snow levels (up to 5-6K feet). Precipitation over the valley is expected to remain below an inch.
The strongest storm in this series is forecast to hit the region Wednesday night into Thursday with strong southerly winds and heavy precipitation. 1-2 inches of rain will be possible in the valley.
Several feet of snow will be possible across the northern Sierra mountain passes with snow levels around 5500-6500 feet.
Wind gusts in the valley may exceed 40 mph with gusts over 60 mph in the mountains. We’ll continue to monitor trends and potential for significant travel impacts from these mid to late week systems.
Extended Discussion (Friday through Monday)
Showers linger into Friday as the upper trough exits eastward. Most of these showers should be light and focused over the northern mountains by evening as upper level ridging builds in.
Models continue to show another trough moving in for the weekend, with precipitation spreading from north to south starting Saturday evening. Widespread precipitation is expected Sunday, though rainfall amounts are expected to be fairly light. Snowfall amounts in the mountains also currently look to be limited to a dusting to a couple inches.