By Philip Mote, Climate Impacts Group, University of Washington

The Climate Impacts Group (CIG) at the University of Washington held two workshops on climate and water resources in the Pacific Northwest during October 1998. The purposes of the workshops were: (1) to present some research results of the CIG and (2) to obtain feedback from participants on the uses of climate information and seasonal forecasts and on the utility and possible future directions of CIG research.

Participants came from a variety of backgrounds. Representatives from several federal agencies, state agencies from Idaho, Oregon, and Washington, regional and tribal entities, and urban water supply and power interests attended the workshops. Participants also came from other universities and from the private sector, including farmers and a representative of a ski area.

The program covered climate variability and hydroclimatology of the Northwest, the long-range climate forecast for winter 1998-99, long-range streamflow forecasting, and a retrospective of the 1997-98 El Nino. Lunchtime talks described the National Assessment of climate change and the implications of climate change in the Northwest.

Selected participants presented operational perspectives on the use of climate forecasts. Some had used seasonal forecasts, but noted disadvantages and barriers. For example, managers of major reservoirs are constrained by many competing priorities that could, to some extent, be alleviated by better forecasts; yet current operating rules require drawing down the reservoirs at a predetermined rate until December 31, when the first streamflow forecasts are available. A representative of the ski industry likened her business to farming: very weather-dependent and reliant on a 5-month season to make all its income. Seasonal forecasts have a huge impact on public perceptions and, therefore, on the ski resort's budgeting.

Response from participants was enthusiastic. Several had never before heard of the Pacific Decadal Oscillation (PDO), a slow climate variation whose impacts on the Pacific Northwest rival those of El Nino. Some who use climate information in decisions were keen to include the PDO as will as El Nino. Doug Bloem, from the Portland Water Bureau (PWB), said that Portland has an unfiltered water system that is vulnerable to high streamflow events (which increase turbidity). If the PDO shifts to negative and such events become more common, PWB may have to spend $250 million to meet clean water requirements (which are based on turbidity data that go back only to 1976, and hence are drawn entirely from a positive phase of the PDO). Hossain Parandvash, also from PWB, produces forecasts of water demand on time scales of years to decades, and was very interested in collaborating on climate change impacts.

In panel discussions, a recurring theme was the need for more specific seasonal forecasts. Another important theme that emerged was the potential value of being able to diagnose, in real time, a shift in the PDO. In short, PDO prediction could have benefits that rival (in dollar value) El Nino prediction for the Northwest. In summary, these workshops appear to have been very effective at communicating with stakeholders. This communication was clearly two-way: their comments are likely to influence our research, and our results are likely to influence some of their procedures and decisions.

For more information, contact:

Philip Mote, Climate Impacts Group, University of Washington; P.O. Box 354235; Seattle, WA, 98195; phone: (206) 616-5346; email: phlip@atmos.washington.edu.