The terrestrial water cycle includes the atmospheric component (water vapor, clouds, and precipitation) and the land component (surface and subsurface runoff, infiltration, evapotranspiration, snowmelt, river flow). Hydrometeorology plays a major role in weather and climate and strongly affects human activities.

Historically, the science and practice of hydrology has focused on land-related processes and has relied on prescribed atmospheric inputs (from observations or atmospheric model outputs, or through empirical estimates derived from conventional meteorological measurements). In other words, the land-generated feedbacks to the atmosphere have usually not been considered. In contrast, while the atmospheric sciences generate hydrologically-relevant forecasts, they tend to avoid dealing with the details of processes influencing feedbacks generated by the land surface.

The purpose of the UA Hydrometeorology Program is to become the first and premier Hydrometeorology program in the World. Our mission is to:

Educate students by providing them with (1) a well-rounded background in the related fields of atmospheric, hydrologic and systems sciences, (2) the tools and methods for numerical modeling, prediction and data assimilation (surface hydrology, weather and climate), and (3) the sensors, data sources and data manipulation tools, including remote-sensing and geographic information systems (GIS); Partner with various national and international weather and climate forecasting agencies to identify critical hydrometeorological knowledge gaps, to support, encourage, and facilitate research in multidisciplinary hydrometeorological science, and to work towards improved forecasts and forecast support (particularly over arid and semiarid regions, such as the Western US), and; Serve the hydrometeorological science and operational communities by coordinating meetings and workshops seeking to build consensus related to hydrometeorological science and to assist in the transfer of advances in understanding into the decision-making arena.