Hot and dry weather expected into next week. Temperatures will be increasing to well above average on Friday and Saturday.

Discussion

Clear to partly cloudy skies cover the region early this morning. A few thunderstorms have been ongoing across eastern Tuolumne County since late Tuesday evening as a weak disturbance moves across central California. The cooling trend continues across the area as surface pressure gradient is a little stronger onshore and the marine layer has deepened to around 1.5k ft. Current temperatures are running around 4-8 degrees cooler compared to 24 hours ago and are in the 50s and 60s in the mountains, and 60s and 70s across the Central Valley (except mid 50s near the Delta).

Slight possibility of thunderstorms on the east side of the Sierra south of Lake Tahoe today

Showers and thunderstorms are expected to end in the northern Sierra early this morning as the disturbance shifts east. Diurnal activity this afternoon and Thursday afternoon is expected to develop mainly to the east of the crest.

Highs today will be similar to Tuesday’s, then hotter weather returns heading into the weekend as high pressure builds westward and marine influence inland is suppressed.

High temperature loop shows widespread triple digits for Friday and Saturday

High temperatures will return to the century mark, or above, throughout the Central Valley on Thursday. On Friday and Saturday, highs are expected to be mostly in the 105 to 110 degree range in the valley resulting in areas of major heat risk. Overnight lows will also return to the upper 60s to mid 70s through most of the valley and foothill thermal belts at the end of the week.

Major heat risk for Friday and Saturday - again. Major Risk for heat-related illnesses for pets, livestock, and much of the population, especially anyone without effective cooling and/or adequate hydration. Impacts likely in some health systems, heat-sensitive industries and infrastructure.

With hotter temperatures returning, be sure to continue to practice heat safety. Additionally, local rivers and streams are still running fast and cold due to mountain snowmelt. Those planning to seek relief from the upcoming heat should properly prepare for cold water temperatures and always wear a life jacket if participating in water recreation.

Extended Discussion (Sunday through Wednesday)

Interior NorCal sandwiched between upper troughing to the NW and upper high over Desert SW through the extended forecast period. Minor cooling expected into Monday, then slight warming Tuesday into Thursday. High temperatures forecast to be near to slightly above normal with continued dry weather.