This town hall meeting will provide an opportunity to discuss the definition of “atmospheric river” as it is being developed for the Glossary of Meteorology. The current atmospheric river draft definition reads as follows: A long narrow and transient corridor of anomalously strong horizontal water vapor transport that is typically located in the lowest 3 km of the troposphere and associated with a low-level jet stream ahead of the cold front of an extratropical cyclone. The water vapor in atmospheric rivers is supplied by tropical and/or extratropical moisture sources and atmospheric rivers frequently lead to heavy precipitation where they intersect topographic or other lower-tropospheric boundaries, or enter into the warm-conveyor-belt-related isentropic upward air motion. Atmospheric rivers conduct over 90% of all poleward water vapor transport in the extratropics in less than 10% of the zonal circumference of the globe. For additional information and to participate in this discussion, please contact F. Martin Ralph ([email protected]).