Severe summer thunderstorms caused over 25% of scheduled departures from LaGuardia Airport to be canceled. More than 630 flights from New York area airports faced cancellations by Tuesday morning. The National Weather Service issued a flood watch and warned of damaging wind gusts. Airlines like American, Delta, JetBlue, and United offered travel waivers for affected passengers. Passengers should check airline websites for the latest flight status and rebooking options.