The Valley has been blanketed in thick Tule fog in recent weeks, which may remind some Valley residents of years past. So why is it unusual to see these conditions now, and why are they so different than in the past? San Francisco Chronicle Meteorologist Anthony Edwards breaks down what’s changed. Plus, the latest news headlines: Valley Congressmen re-introduce legislation to prevent illegal biomedical laboratories; and the CEO of a Fresno health care company faces fraud allegations.