Major U.S. airlines issued travel advisories for Houston airports and dozens of other cities ahead of a winter storm expected to disrupt flights. Southwest, United, Spirit, and Frontier announced flexible rebooking policies, fee waivers, and broad lists of affected airports. Passengers traveling through impacted cities on specified dates can change plans under outlined conditions, including same-city and same-cabin requirements for some carriers. Travelers are urged to confirm flight status and review airline-specific guidelines before heading to the airport as carriers prepare for delays, diversions, and cancellations linked to the approaching weather system.