April 10, 2020 – Dry and increasingly warm into next week, with some breezy wind at times.
Upper level low is currently centered around Los Angeles. Overnight wraparound showers on the northwestern portion of the low have shifted out of our area to the southwest, most recently bringing some light rain over the Stockton to Tracy area. Low and mid clouds continue over much of the area, though on satellite some breaking up of the cloud deck is evident over the Valley. Local foggy/misty conditions are over portions of the foothills and into the mountains and will continue through this morning. Dry weather is expected today across the area, with decreasing clouds.
The closed low will move southeastward across Southern California Friday and then over southern Arizona on Saturday. High pressure will build over Northern California Friday into early next week. This will bring dry weather and warming temperatures to interior NorCal. Valley temperatures will warm into the 70s Friday with temperatures around 80 for the northern Sacramento Valley Saturday into Monday.
The only precipitation potential in the short term is from a brief impulse tracking over the ridge Sunday. This could bring a slight chance of showers to the Sierra south of I-80 Sunday afternoon. Precipitation amounts are expected to be light, and snow levels will be over 8000 feet.
Extended discussion (Tuesday through Friday)
The offshore ridge across the east Pacific shifts its way back toward the West Coast. In response, heights will gradually build allowing for a further uptick in temperatures. From Tuesday through Thursday, Valley and Delta highs are forecast to sit in the upper 70s to low 80s. Model 850-mb temperatures are expected to be around 15C over the northern Sacramento Valley. If the surface to 850-mb layer becomes well mixed enough, cannot rule out highs approaching 85 degrees during this period.
By later in the week, ensembles show some lowering of heights in response to the approach of a trough. Deterministic models depict this in the form of a closed low which nears the California coast next Friday. Poor run-to-run continuity in these models suggests below average confidence here. Temperatures lower by around 5 to 10 degrees with an increase in cloud cover. Precipitation chances are uncertain but worth keeping an eye on.