July 31, 2020 – Dry and seasonably hot conditions are expected to continue across the region into the weekend. Cooling returns next week.
Discussion
Skies are clear across interior NorCal early this morning, except for coastal stratus west of Cordelia. The Fort Ord Profiler indicates the marine layer depth is around 1600 ft, enough to continue strong Delta flow. Early morning temperatures are generally running 2 to 5 degrees cooler than 24 hours ago.
Dry and seasonably hot conditions will continue today into the weekend as ridging over the Desert Southwest extends into NorCal. Daytime temperatures will generally reach the mid to upper 90s across the Valley, except for northern locations where highs will reach the triple digits around Redding.
Saturday highs will nudge a few degrees warmer compared to today. Then, marine influenced areas should stay a bit cooler on Sunday due to increased Delta flow.
Ensembles depict a trough moving through the PacNW early next week. This should bring slightly cooler temperatures on Monday, especially for marine/Delta influenced areas given increased Delta flow.
Extended Discussion (Tuesday through Friday)
Weak upper level troughing will linger over NorCal next week. This will allow temperatures to cool to near or below normal as well as bring an increase in onshore flow and associated Delta Breeze.
Daytime temperatures will be in the upper 80s to upper 90s in the Valley, low 80s in the Delta region, and 70s to upper 80s in the mountains and foothills. Ensembles indicate an increase in moisture over the mountains Wednesday and Thursday, but at this time instability looks too low for any thunderstorms.