You can't say this heat wave snuck up on us, it has been in the forecast for a week and a half. Computer models have not blinked and if anything are showing more commitment to the notion of a powerful ridge setting up shop over the entire West Coast.
Inland temperatures Friday-Monday look to have 100-115 potential. 115 is the all-time record high in Paso Robles tied three years ago yesterday. Regardless of hitting the all-time record or not the daily records look reachable during the period. Coastal valley record temps also look breakable.
The reason for this blast of hot weather is a ridge of high pressure is building over The West. Friday through Monday the ridge over The West amplifies. The strength of the ridge is potentially historic, it is at least a 1 in 10 year event and potentially much more rare than that.
The ridge will drive offshore flow, 10-20 mph offshore winds with some higher gusts Friday-Monday mornings. Looks like the winds should switch back to NW each afternoon and become gusty up to 20-30mph at the coastline, but this breeze may not extend far inland or last long enough to provide much relief. Water temperatures are also relatively warm for our area after a summer of heating so the cooling could be muted from the onshore switch.