A special session entitled “Large Scale Climatic and Hydrologic Variability and Interactions” was held at the 1986 AGU Fall Meeting in San Francisco, Calif. Sponsored jointly by the Hydrology and Atmospheric Sciences sections, the conference objective was to explore the current state of understanding and methods of analysis appropriate to climate and hydrologic processes on large time scales (e.g., seasonal or annual) and over broad areas (e.g., continental). In particular, the interactions between climate and hydrologic processes and observed variability were addressed.