A winter storm called a “Bomb Cyclone” for its extreme snowy conditions and sudden arrival is expected to slam the East Coast this week. American, Delta, JetBlue, and Southwest are waiving ticket-change fees as more than 3,200 flights were grounded. JFK, among the nation’s busiest airports for international travel, was shuttered in anticipation of heavy snows, ice, and bitter cold. While state officials scramble to mitigate the impact on the ground, travel is expected to be disrupted into Friday.