Alan F. Hamlet Dennis P. Lettenmaier Center for Science in the Earth System Climate Impacts Group and Department of Civil and Environmental Engineering University of Washington March, 2005 Water Management Applications of Seasonal to Inter-Annual Climate Forecasts

A Changing View of Climate: Pre 1990: “Climate is something that happens.” Climate is the long-term statistics of weather Weather is unpredictable at long lead times, therefore climate is unpredictable at long lead times Post 1990: “Climate (and its impacts) is something that is understandable and potentially predictable.” Climate phenomena are potentially predictable in their own right, and partly determine the probability distributions of weather events.

A history of the PDO warm cool warm A history of ENSO Pacific Decadal OscillationEl Niño Southern Oscillation

Climate forecasts make possible more sophisticated risk assessments Naturalized Streamflow at The Dalles, OR

Climate Forecast Streamflow Forecast (supply) Water Management Decisions Conceptual Overview of the Use of Climate Forecasts for Water Management Demand Forecast Hydropower Irrigation Urban Water Supply Flood Control Fish Flows

Potential value of streamflow forecasts from Maurer and Lettenmaier, J Clim, 2004

CIGStakeholders Strategies Continual networking to identify partnerships Workshops & surveys provide means for initial contact Capitalize on climate events Long-term commitment OutreachPartnershipsEducation

CIG Annual Water Workshops

Progress Resulting from Education and Outreach from the CIG to the PNW Water Management Community Familiarity with terminology and concepts associated with interpreting climate forecasts Understanding of the fundamental relationships between climate variability and natural resources such as snowpack, streamflow, and associated risks of droughts and floods. Understanding of risks and uncertainties associated with regional impacts of global warming. Understanding of forecasting techniques incorporating climate forecasts and information. Understanding opportunities for water management applications

Progress Resulting from Education and Outreach from the Water Management Community to the CIG Understanding of the spatial and temporal scales at which climate information and resource forecasts must be provided to be useful. Understanding that climate and resource forecasts must function within a larger framework of management concerns. Importance and role of institutional characteristics in the process of bringing forecast innovations to bear on actual resource management problems. “Give us the raw data.” [transparent process] Official products from authorized sources.

Seattle Public Utilities (in-house statistical forecasts) BPA has recently (last two years) incorporated an ESP forecasting system developed by the PNWRFC and has assimilated the forecasting techniques described here. Seattle City Light (Skagit River) Forecasts provided by private consultant Tacoma Power (Cowlitz and Nisqually Rivers) Forecasts provided by private consultant PacificCorp (Lewis River) Forecasts provided by private consultant U.S. Army Corps of Engineers (statistical forecasts for Dworshak and Libby using SOI) Portland General Electric (ENSO-based streamflow forecasts) PNW Early Adopters of PDO/ENSO Streamflow Forecasts

From Scientific Research to Operational Climate Service Applications Track 1 Climate Forecasting Systems Track 2 Hydrologic Forecasting Systems and Water Management Applications Track 3 Education and Outreach Track 4 Technology Transfer and Operational Design New Idea: Climate is Predictable

Track 2: Hydrologic Forecasting and Application Development Development of streamflow forecasting methods Demonstrations of forecast skill Experimental application to water resources management Feasibility studies Implement and test quasi-operational pilot products Technology transfer to operational agencies

Partnerships between academic researchers and operational forecasting agencies can help bridge the gaps between experimental research products and official operational products. Examples: NRCS / University of Washington (Experimental use of UW West-Wide forecasting system) NWS Colorado River Forecast Center/ CIRES Western Water Assessment (ESP-post processing incorporating climate forecasts)

So what’s happening this year?

Discussion and Conclusions It takes a long and sustained effort to bring new forecasting products from an academic to an operational setting, and a number of closely integrated parallel tracks are required if the effort is to be successful. Scientific research groups and operational service agencies play complementary roles and bring different kinds of funding and resources to the task of developing and disseminating new climate and streamflow forecasting products. After eight years of experimental development, outreach and education by the CIG (and others), PNW water managers, policy makers, and service agencies are showing clear signs of moving toward operational implementation of long-range climate and streamflow forecasts to improve water management in the PNW. Despite early adoption by a number of autonomous water management agencies, we still have a long way to go in providing fully operational long-range streamflow forecasts incorporating climate forecasts to a broad user community. Strategic planning to invest in the process and effectively use the strengths of various participants in the process will be essential to a successful outcome.