A very warm holiday weekend coming up as strong high pressure aloft combines with weak onshore flow to push temps well above 100 in the SLO county interior valleys.
Most areas will continue gentle warming Saturday and pop up to another 5-10 degrees Sunday as offshore flow develops for the morning hours.
Sunday night into Monday the upper high starts to weaken and shift to the east. As this happens the flow aloft shifts to the southeast which will help pull in monsoon moisture from Mexico. Most of the moisture and instability will remain east and south of