SAN FRANCISCO — An unusually dry winter has spelled trouble for parts of California.
Air quality in the San Francisco Bay Area and Central Valley is the poorest it's been in years. State fire officials have warned of an increased fire danger in Northern California, and ski resorts in the Sierras have been forced to turn to artificial snow.
December was among the driest on record in Northern California. The state Department of Water Resources reported the snowpack water content throughout the Sierra at 19 percent of the average for early January.
And rain is not in the forecast for at least the next week, according to the National Weather Service.
The lack of rainfall and wind has kept car exhaust and smoke from factories and chimneys in place, leading to repeated violations of federal health standards for fine particle pollution in the San Francisco Bay area and Central Valley.