SAN FRANCISCO (AP) – The year’s fire danger warning in Northern California is putting Pacific Gas & Electric on alert. The utility said starting Saturday morning, it might turn off power to thousands of customers in areas north of San Francisco and in the Sierra foothills to help reduce the risk of fire. That’s where the state’s most destructive and deadliest wildfires occurred the last two years. Forecasters predict hot and dry conditions starting Friday and winds blowing 15 to 30 mph, with gusts of up to 45 mph. The National Weather Service said humidity could drop to 10 percent. The warning extends to 5 p.m. Sunday. It covers inland valleys below the 1000-foot level, where fire officials say grass and shrub have dried despite an unusually rainy May across the state.