Dry and increasingly hot weather into this weekend with widespread Major Heat Risk. Temperatures will trend less hot next week, near normal by mid week. Excessive Heat Warning from 11 AM Saturday to 11 PM PDT Sunday.
Discussion
Temperatures will be noticeably warmer today as high pressure ridging over the Desert Southwest extends westward with widespread triple digit highs across the Valley, Delta and foothills.
Widespread moderate heat risk is expected on today with some local major areas in the central valley northward and in the foothills. The high pressure ridge will build northward over the weekend peaking over the region on Saturday.
Record or near record heat is expected this weekend with Widespread Major Heat Risk.
The ridge will begin to move eastward slightly on Sunday but temperatures are expected to remain near Saturday’s highs.
In addition low temperatures will be the warmest Sunday morning with mainly 70s for the the valley while thermal belt areas in the foothills will only cool off to near 80 degrees. As a result of those very warm overnight lows areas in the foothills will experience Extreme Heat.
The mountains while very warm are expected to cool off enough and with the lower daytime highs are expected to stay in the Moderate heat risk category.
A trough moving into the Pacific northwest on Monday will bring some synoptic cooling to the region along with helping to increase the strength of the Delta breeze starting late Sunday.
Temperatures will be trending cooler but there will still be a moderate heat risk expected for most locations. Continued moderate to strong Delta breeze is expected for Monday night that will lead to better cooling for Tuesday.
Extended Discussion (Tuesday through Friday)
Upper troughing over NorCal Tuesday into Wednesday gives way to building high pressure from the Desert SW towards the end of the week. High temperatures will be near to slightly above normal midweek, trending up late in the week. Dry weather continues through the extended forecast period.