Snow and freezing temperatures in parts of the South, the Midwest and the Northeast are having a huge impact on air travel. 50 flights were cancelled at SFO, with the biggest number of those impacting flights into or out of Dallas, which is bracing for winter weather. Major airlines are proact ively cancelling flights at airports with the worst weather. SFO says if these cancellations keep up, they are prepared to set out coats and blankets for stranded passengers and to keep concession stores open extra late. Alyssa Goard has more information in the video player above. ...read more read less