February 13, 2017 – Dry weather continues through Tuesday. Yet another round of wet weather arrives Wednesday with several rounds continuing through next weekend.
Discussion
Upper ridge continuing dry weather across the region. Lots of high cloudiness is spilling through the ridge and may inhibit much valley fog formation early this morning. Temperatures remain rather mild and range from the 20s and 30s in the mountain valleys to the 40s elsewhere.
Dry weather expected to continue today and Tuesday, though a few model runs have been indicating some very light QPF for this evening over the northern mountains as the weak wave presently centered around 38N/135W brushes far northern California. Satellite imagery indicates a plume of TPW of 1.2-1.5 inches ahead of the wave.
Valley temperatures will warm into the 60s today and Tuesday with 40s and 50s across the mountains. Nevertheless, high water issues will remain a problem for some areas, so the flood warning continues. Hillsides remain water logged and will take several days to dry out and become more stable, just in time for more rain.
The next more impactful storm is forecast to move through the region later Wednesday into Thursday. Some light precipitation may begin across far northern California as early as Wednesday morning, but more significant precipitation will likely hold off until Wednesday night and Thursday morning as the front moves through the area.
The Sacramento Valley may see 1/2 to 1 inch of rain while the foothills and mountains may see as much as 2-4 inches. Snow levels will lower to around 6-7K ft by Thursday, allowing the higher peaks to receive a foot or more of new snow while the passes are expected to see generally less than 6 inches.
Extended discussion (Friday through Monday)
Long term models continue to advertise an active pattern across interior NorCal during the extended period. A series of Pacific fronts are forecast to move through the region Friday into Monday, bringing periods of widespread precipitation. Early precipitation amounts show generally 1 to 2 inches across the Valley and 2 to 4 inches over the mountains Friday through Sunday night, with some higher amounts (up to 5 to 6 inches) over western Plumas County and Lassen Peak.
Of course, these higher amounts over the Feather River basin will contribute more runoff into Lake Oroville. The good news is that some precipitation will likely fall as snow. Snow levels should start out 5 to 6K feet Friday and Saturday, and lower to 3 to 5K feet Sunday and Monday. This is a long ways out to determine precip amounts and snow level accuracy, so these amounts will likely change. Gusty southerly winds could be possible with these systems.