October will arrive tomorrow (Saturday) along with a change in the weather.
A significant cooling trend is expected into early next week, with periods of gusty winds as cold low pressure from the Gulf of Alaska approaches and moves through Northern California.
Periods of gusty winds will continue today, which also increases the threat of fire, especially over the higher terrain.
High temperatures are likely to be fifteen to twenty-five degrees below normal by Sunday. High temperatures in the Northern San Joaquin Valley will be in the sixties. High temperatures in the Mother Lode and the Sierra Nevada will range from the forties to the fifties. New records for the lowest high temperature are likely for October 2nd (Sunday).
Widespread showers are expected on Sunday into early Monday. Isolated thunderstorms are possible in both the Central Valley and the Mother Lode on Sunday afternoon. There is the potential for small hail near thunderstorms.
The National Weather Service has issued a Winter Weather Advisory for the Sierra Nevada above 6,000 feet from 11 AM Sunday through 5 AM Monday.
Up to three inches of snow accumulation is possible above 6,000 feet.
Decreasing showers are expected on Monday.
A Winter Weather Advisory means that periods of snow will primarily cause travel difficulties. Be prepared for snow covered roads, limited visibilities and use caution while driving.