Shower and thunderstorm chances will continue mainly over the higher elevations into next week with best chances in the afternoon and evening hours. Temperatures warm back up the next few days before we see gradual cooling over the weekend into next week.
Discussion
Four corners ridge will begin to build back west today bringing warming temperatures. Highs will be about 6 to 12 degrees warmer than yesterday. A weak short wave will move over the ridge into NorCal during the afternoon and evening. This will once again bring mid to high level clouds across the area and chances for showers and thunderstorms. The chances will mainly be in the Coastal Range but we will also see slight chances at the Sierra Crest.
This short wave will pull in some moisture from Tropical Storm Frank keeping high PWATs of 1.0 to 2.0″ across the area. Heavy rain will be likely with any thunderstorms that develop. Cloud cover will impact the amount of instability that builds in and will impact how widespread thunderstorms become.
Precip chances diminish towards sunset and the upper level ridge will continue to build in into the end of the week. This will bring seasonably warm temperatures with the heat peaking on Thursday.
High moisture will remain in place over the region and this is going to keep thunderstorm chances in the forecast for the afternoon and evening. Chances will remain over the Sierra with the best chances towards the crest. Heavy rain will also continue to be a threat with any thunderstorms.
We will see some cooling Friday and Saturday with the ridge flatting as a trough pushes into the PacNW.
Extended Discussion (Saturday through Tuesday)
Ensembles are struggling with the timing but the upper level low over the Pacific looks to push east during the extended period. This will help to push the ridge back east and will bring gradual cooling. Elevated moisture remains in place keeping thunderstorm chances in the forecast for the afternoon and evenings over the Sierra.