The Town Hall provides an opportunity to discuss the definition of “atmospheric river” as it is being developed for the Glossary of Meteorology. Atmospheric river draft definition: 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 percent of all poleward water vapor transport in the extratropics in less than 10 percent of the zonal circumference of the globe.