February 15, 2020 – Slight chance for mountain showers Sunday otherwise dry. Above average temperatures continue. Breezy winds early next week.
Discussion
We will remain on the eastern edge of the Pacific ridge today. This is bringing light winds and quiet conditions this morning. Some patchy fog will be possible from Sacramento south into the San Joaquin Valley but not expecting the fog to be very dense. Passing high clouds are expected for the morning with increasing clouds during the afternoon and evening as our next system pushes into the PacNW and brings weak warm air advection to the area. A weak frontal boundary will push into the region Saturday night into Sunday bringing chances for light showers mainly in the higher elevations north of I-80. Precip will be light with little to no accumulating rain or snow. Shower chances diminish by Sunday evening.
The short wave trough will then dig into the Great Basin on Monday and this will tighten up the pressure gradient across NorCal. This will bring breezy northerly winds with gusts up to 25-35 mph in the valley with higher values in the mountains and upper foothills. Upper level ridging builds back in on Tuesday calming the winds. Temperatures throughout the period will be near to slightly above average.
Extended Discussion (Wednesday through Saturday)
Upper trough drops into NorCal in a “inside slider” fashion Wednesday. Moisture is limited with this disturbance and main impact will be some locally breezy conditions over the mountains. Upstream Pacific short wave approaches Thursday, but models differ with strength of it. EC brings open wave across CWA Friday while GFS has stronger closed low and develops some precip over the Sierra Nevada. Ensemble solutions support EC solution and for now will maintain dry forecast. Upper ridging builds in behind this system Saturday.