This three-year research project seeks to extend and broaden a program that is dealing with the growing season (May-August) rainfall of the region bounded by the Rocky and Appalachian mountains, the Gulf Coast, and approximately 55 N in Canada. The fundamental goals to date have been to: (i) identify the characteristic spatial patterns of rainfall variation for 1949- 80; and (ii) quantify the "local" climate system processes/conditions (those occurring over and adjacent to study region -- water vapor occurrence and supply, troposphere's predisposition to provide uplift) contributing to the contrasting rainfall patterns of three case study years (1975, 1976, 1979). The PIs will (a) extend and complement the aforementioned rainfall analyses; (b) complete and integrate the above "local" case study investigations; and (c) initiate inquiry into the wider climate system causes of the region's growing season rainfall variations. This research is important because it seeks to understand regional climate variability in the context of more global climate features and forcing.
