September 9, 2019 – A weather system will bring a chance of showers to the mountains Tuesday, otherwise below average temperatures continue into mid- week. Warm and dry weather returns for the end of the week.
Discussion
Other than a few clouds across the northern half of the forecast area, skies are clear across the region early this morning.
Current temperatures are a little milder across most of the area compared to 24 hours ago and generally range from the 30s in the mountain valleys to the upper 50s and 60s across the Central Valley.
Upper trough will deepen along the West Coast into Tuesday. The main closed low will remain to the north over the PacNW, but several short-waves will pivot through NorCal.
May see an isolated storm pop near Mt Lassen this afternoon, but the main chance for showers will occur Tuesday over the mountains as a stronger wave moves through.
Temperatures and humidities will moderate through Tuesday as the trough brings additional synoptic cooling. Temperatures are forecast to rebound Wednesday as the trough shifts east and northerly surface flow develops. Strengthening upper ridge returns temperatures to above average beginning Thursday.
Extended Discussion (Friday through Monday)
Operational models similar next Friday with upper ridging continuing to influence NorCal`s weather. Models then diverge over the weekend with GFS building EPAC ridge inland while EC digs short wave trough along the West Coast. GEFS/EPS support troughing solution though not as deep as EC which would suggest some precip possible late Sunday into Monday. For now will forecast a cooling trend through the extended with some cloudiness.