Cloud computing is becoming pervasive in a broad range of computational domains and is being explored to determine the benefits to the Weather, Water and Climate community. The cloud promises lower cost, ease of use, ease of access, and flexible provisioning, but there are challenges to gaining these benefits and the cloud may not be appropriate for all workloads. This session solicits papers presenting experiences in using HPC in the cloud for Weather, Water and Climate applications as well as analyses addressing suitability of cloud platforms for delivering HPC to various Weather, Water and Climate applications. Speakers will address challenges and lessons learned from the experience, including issues of issues of performance, availability, data storage, data transfer and security.