...U.S passenger enplanements grew at a modest 1.3% for all of 2013, a comparable level to the 1.4% growth rate in the prior year. Heading into 2014, traffic levels were expected to pick up at a slightly improved pace based on general economic improvement; however, the severe winter weather conditions led to an exceptionally high level of flight cancellations at many major U.S. airports. Still, this "shock" is only likely to have a temporary effect on overall traffic growth given its occurrence during months with lightest travel demand....