11:20p update from Chief Meteorologist Dave Hovde:
Some monsoon instability did creep into the area tonight producing a few rain showers in the SLO to 5-Cities area. Most folks likely miss this activity but it is definitely a non-zero rain chance.
Tuesday the Central Coast saw much of the interior crack 100 while a wide variety of temps were found elsewhere.
There is even a heat advisory in place that will remain in place thru Wednesday evening for the deep interior for more hot weather locally tomorrow.
The Southern Salinas River Valley will see some easing of temps Wednesday but 100 is still on the table, not quite warm enough to join the advisory area but close.
Away from the interior, the same temperature trend is there: down a little. The marine presence will fluctuate over the next few days but no huge swings as marine presence smooths out the spikes in trends near the coast.
While Wednesday will likely see some temp drops, Thursday and Friday likely see temps recover. Inland heat could return to the 100-105 range Friday and coastal valleys in the upper 70s and 80s (limited change at beaches).
The weekend will see a much more significant drop in temps, back down to average inland Saturday and even below average Sunday before more warming early next week. Again coastal valleys and beaches will follow the trend direction but the changes in temps will likely stay within a 5-7 degree range.
The reason for the drop Wednesday will be that SW flow aloft returns for a short stay, this is generally a moderating direction this time of year for the Central Coast. There is also a mid-level low working thru that flow. Thursday and Friday ridging returns. The weekend will see an upper-level low work thru the PacNW which will weaken regional high pressure a little and allow for some cooling. Once it departs it looks like a larger ridge develops for more warm inland weather as we draw close to the end of the month.