October 13, 2019 – Quiet weather is expected into early next week. Near average temperatures, then cooler than normal temperatures mid to late week. A weather system could bring a chance of showers late week into next weekend.
Discussion
A short wave trough will be pushing into NorCal today. No rain is expected with this trough but it will bring some cloud cover to the area. The trough pushes to the east on Monday and we will see a ridge build in. This will bring quiet weather for the start of the week. A deeper trough will push south mid-week and this will bring some shower chances to the area starting Wednesday night. The EC ensemble is further south with this system and would give us a better chance for rain while the GFS ensemble is more north giving us lesser chances for rain. Both ensembles show a cold front moving over the area Wednesday night and that would be the greatest time frame to see activity.
We are seeing chilly temperatures once again this morning across the area but they are staying a bit warmer to the north where there is some cloud cover. Overnight lows tonight look to be a bit cooler then what we saw this morning continuing to run below normal. Daytime highs will be right around average for this time of year.
Extended Discussion (Thursday through Sunday)
A Weak shortwave trough passes to the east of the state on Thursday leaving flat high pressure and zonal flow over NorCal for most of the extended period. More shortwave troughs moving through this zonal flow will bring the threat of showers to the northern mountains on occasion but timing and strength of these systems will be very difficult so confidence in precipitation chances will be fairly low.
Most of the forecast area will remain under dry and cool conditions with daytime highs remaining well below normal going into the weekend. Upper ridging is forecast to start rebuilding over the west coast early next week for a start of a warming trend going into early next week.