Air travelers were keeping a wary eye on Hurricane Matthew as forecasts continued to show it tracking toward the U.S. East Coast later this week. Underscoring the ominous forecast, several big U.S. airlines have extended their Matthew-related change-fee waivers to cover U.S. airports. That all comes as Matthew churns through the Caribbean and looks increasingly likely to at least come close to Florida and other East Coast states. A U.S. landfall remained a possibility by late week, though the storm’s projected path still had a large degree of uncertainty.