Bay Area winter pollution worst in years

If you’re keeping count, there have been 12 Spare the Air days since Nov. 1 in what’s shaping up as the worst winter of air pollution in the Bay Area in years. Worst day so far: Christmas, with all that extra fireplace smoke. A stubborn high-pressure system is pushing storms away from Northern California, something weather experts say isn’t expected to change soon, the Chronicle’s Peter Fimrite says.