Requires the Comptroller General (GAO) to study how well local, state, territorial, and Federal emergency alerting systems exchange timely, useful information during weather-related emergencies. The study will evaluate which alert methods work best (including social media), whether guidance and training support clear, actionable alerts, and whether outdoor alert systems (like sirens) could be improved with input from emergency managers and community groups; GAO must report to Congress within 18 months of enactment.