June 28, 2020 – Significant cooling continues today with a slight chance of late day showers over the higher Sierra Nevada. Breezy northerly wind today and Monday with below normal temperatures, then dry with near normal high temperatures Tuesday through Saturday.
Discussion
Heights/thicknesses continue to lower today as upper low moves through the PacNW into the Intermountain West. Models showing associated precip remaining mostly outside of our CWA with a few showers possible over higher elevations of the Sierra Nevada late in the day. Strong flow through the Carquinez Strait expected to weaken slightly this morning but remain quite breezy today.
Gusty northerly wind also expected in portions of the Sacramento Valley today as strong NWly winds aloft mix down. High temperatures expected to be upwards of 15 degrees cooler today with mid 80s forecast in the Central Valley and 50s to 70s for the mountains and foothills.
Upper ridging builds inland over NorCal tonight and Monday as EPAC surface high extends into Oregon. Breezy northerly wind continues over portions of interior NorCal into Monday. Increased fire concern results and Red Flag in place to address this. Max temperatures rebound back up several degrees tomorrow to near or slightly below normal.
Subsidence continues over interior NorCal Tuesday with additional AMS warming. MOS guidance suggests highs will be around 2 to 5 degrees higher than Monday. Lighter wind expected Tuesday under weaker pressure gradient. Little change in forecast high temperatures for Wednesday.
Extended Discussion (Thursday through Sunday)
Weak upper trough centered just off the West Coast favored by the ensembles for the second half of the week and next weekend. Dry weather with temperatures close to average expected.