Climatic teleconnections for influencing California reservoir operations: Identification, assessment, and constraints

Studies have shown the presence of coupled variability patterns between antecedent climatic conditions of the Pacific-region and Western U.S. hydrologic variations. Despite demonstration of these patterns (i.e. teleconnections) and the availability of proposals on how to use them in hydrologic forecasting, they remain rarely applied in water resources management.; Two causes for this lack-of-application are addressed from the perspective of California reservoir operations. The first relates to not knowing the impacts of application during decision-making. The second relates to not knowing whether alternative teleconnections exist for a regional hydrology that does not strongly teleconnect with the El Nino Southern Oscillation or the Pacific Decadal Oscillation, (e.g., Northern California).; This research uniquely uses a decision-centric (i.e. “bottom-up”) approach to first identify teleconnections that are relevant to California reservoir operations, and then to frame the valuation of those teleconnections in decision-support. The research-framing decisions relate to supply management: stored-water carryover targeting and water allocation.; The identification phase used several empirical tests to demonstrate the presence of teleconnections between diagnostics of pressure-structure conditions in the midlatitude Pacific atmosphere and seasonal to annual reservoir inflow conditions in Northern California. Teleconnection schemes were found involving each inflow period relevant to both stored-water carryover targeting and water allocation.; The assessment phase showed that the scheme diagnostic related to stored-water carryover targeting (i.e. Z8_{500, June}) offered unique information for water year inflow forecasting and decision-support. However, the scheme diagnostics involving the inflow forecast periods of water allocation offered no added information value relative to that offered by snow surveys, which are coincident with forecast dates. Because the teleconnection and snow survey diagnostics are strongly correlated, it appears that the teleconnection diagnostics are indicative of snowpack conditions on the forecast date, but not of weather patterns persisting into the forecast period.; The third research phase identified teleconnections for easing flood control's constraint on applying Z8_{500, June} to influence stored-water carryover targeting. The teleconnections involve diagnostics of pressure structure conditions in the mid-latitude Pacific atmosphere that are correlated with wet season flood-event potential. This potential dictates the interplay between wet season flood control and stored-water management strategies.