Northern California is in for another cool morning on Wednesday, although the Delta breeze will be less pronounced than it was on Tuesday. The day will be characterized by a mix of sunshine and clouds, with mild temperatures. The mercury will climb to the high 60s to low 70s. The Sierra region may experience some afternoon showers or isolated thunderstorms over the next few afternoons, with the possibility of showers south of Highway 50 on Wednesday. Temperatures will dip on Thursday, and showers are likely in the Foothills and Sierra later in the day. The remainder of the week will bring near to below-average temperatures throughout the region. Friday is expected to be the coolest day, with a small chance of showers in the Valley. The weekend will be dry and will begin to warm up by Sunday.