June 1, 2018 – Dry weather with hot temperatures returning this weekend.
Discussion
Upper level ridge will build today through the weekend and will bring warming temperatures and dry conditions across northern California. Afternoon high temperatures this weekend will range between 10 and 15 degrees above normal for early June. The main heat impacts will be for the west side of the valley and the coastal foothills. Temperatures will cool slightly for Monday, but afternoon temperature readings will remain on the warm side of normal.
Extended discussion (Tuesday through Friday)
Upper level high pressure ridge over the southwest U.S will keep the forecast area dry through the extended period. Southwest flow aloft between this ridge and weak troughing over the eastern Pacific will bring continue onshore flow to NorCal which should keep daytime highs near normal for this time of year.
Winds should remain fairly light however except occasionally breezy through the delta. Models differ a bit towards the end of next week.
ECMWF keeps a stable upper southwest flow over the region while GFS digs a small low off the Bay Area coast next Friday. If this scenario ends up being closer to reality then a more southerly flow aloft might start bringing a return of afternoon mountain showers or thunderstorms. For now, have kept extended period all dry until models better align.