This session aims to grow the international weather and communication network while continuing to build the global knowledge base by sharing the latest research on communicating about High Impact Weather. This session is supported by the World Meteorological Organization’s (WMO) 10-year High Impact Weather (HIWeather) research program, which aims to “promote cooperative international research to achieve a dramatic increase in resilience to high impact weather." Within this program, the Communication Task Team is building capacity in communicating high impact weather information. This is being achieved by bringing together a range of international experts including stakeholders from weather services, the emergency management sector, social scientists, and other key practitioners and researchers, and applying new knowledge and developments in relation to content, language, format, public awareness and dissemination. Determining best practice in executing effective risk or impact based warnings in an end to end warning system context and/or how to apply skill in communicating uncertainty so that communities may better understand and respond to the risk from hazards. While we are keen to include any research on weather and communication, we are particularly interested in hearing from presenters about research and practice in the following areas, which align with the goals of the HIWeather programme: the role of social media, particularly for contributing to impact models and warnings; the influence of trust, salience, beliefs and other factors on communication; communicating uncertainty (including probabilities) and the implications of uncertainty in forecasts and warnings; post-event case studies on communication of weather information and usage of advice in decision-making; best practice in communication training sessions being held with meteorologists on communication; research on communication of hazards including urban flooding, localized extreme wind, disruptive winter weather, wildfire, and urban heat waves and air pollution. The communication task group brings stakeholders together through coordinated activities such as workshops and conference sessions, writing white papers/special issues in journals, and sharing good practice; developing communication projects; conducting surveys; and initiating training courses. For more information, visit https://www.wmo.int/pages/prog/arep/wwrp/new/high_impact_weather_project.html. Please join us if you are interested in finding out more about the WMO HIWeather project and if you can contribute to this global initiative.