1. Pacific Northwest Climate Outlook

Temperatures and precipitation were below normal throughout the Pacific Northwest (PNW) in April, continuing a pattern that has contributed to substantial snowpack in the region this winter. Read more...

2. Pacific Northwest Streamflow Forecast Updates

West-wide Seasonal Hydrologic Forecasts Update (Columbia R., Snake R., and other western-U.S. rivers)

Following prevalent conditions in the previous period, the second part of the water year in the PNW was characterized by below normal soil moisture conditions in the Cascades. Precipitation events occurring late in March led to normal conditions in the coastal areas. Good soil moisture conditions in the PNW contribute to a forecast of normal streamflow values in the upper Columbia basin and slightly above normal in the lower part of the basin. Streamflow projections for the Snake River are also near normal. Snowpack in the Cascades and the Blue Mountains remains above normal.

Graphical depictions of recent estimates of soil moisture, snow water equivalent, and streamflow can be found at the University of Washington's West-wide Seasonal Hydrologic Forecast System website. These experimental real-time forecasts are updated monthly and are based on several climate forecast methods. A number of products at the web-site are also updated on a daily basis. These include basin-averaged water balance conditions for each forecast point, spatial maps of current conditions, and a spatial summary of snow water equivalent for the western U.S.

A related effort that offers daily updates of hydrologic conditions throughout the U.S., can be found on the UW Experimental Surface Water Monitor website. The Surface Water Monitor shows daily updating estimates of hydrologic conditions throughout the U.S. The site also offers weekly projections for soil moisture and runoff across the U.S., for lead times up to 3 months. The broader geographic analysis shows current dry conditions in parts of the PNW persisting for at least 3 months. Since the website's launch in April 2005, the Surface Water Monitor has increasingly become a data source used by U.S. Drought Monitor and Drought Outlook authors in the preparation of their operational products.

3. Exceptional Snowpack - What About Climate Change?!

The past few months have been a delight for Northwest snow lovers. Unusually cool conditions have produced above-average mountain snowpack in much of the PNW, while lowland areas experienced an unusual number of snowfall events. Spokane posted its second snowiest winter ever with 89.5", 4” behind the all-time record set in the winter of 1949-1950. The last half of March was exceptionally cold in the Northwest. Sea-Tac airport broke its record low max on March 28 and Spokane received a record 15.5” of snow during the 15-31 March period.

Throughout the PNW, temperatures over the last 3 months (Feb 14-May 13) were cooler than average while precipitation was extremely low - below 70% of average almost everywhere. How could there be so much snow when the precipitation has been below average? In part, this winter/spring illustrates the temperature sensitivity of our mountain snowpack. In 2005 a few warm storms provided a large fraction of the season's precipitation but built little snowpack. This year, despite the relatively dry conditions for much of the winter, accumulation continued efficiently with little loss to melting due to the cool temperatures.

And what about climate change? Do the cooler than average conditions mean that climate change is over? Unfortunately no, climate change has not gone away. As noted in the current climate outlook, this year is a relatively strong La Niña. La Niña, and its opposite phase El Niño, is an important source of natural climate variability globally and in the PNW. La Niñas generally increase the odds for (but do not guarantee) cooler and wetter conditions in the PNW, while El Niños increase the odds for the opposite. And while Dec-Feb temperatures were lower globally compared to winters of the past seven years, this past Dec-Feb was still very warm globally relative to the past 120 years.

What we are seeing is a tale of two climate events occurring simultaneously at different time scales. El Niños and La Niñas, collectively referred to as ENSO events, occur on seasonal to interannual times scales while climate change is occurring at the multi-decadal to centennial time scale. An analogy is looking at the performance of the U.S. stock market over the last six months relative to the long-term performance of the market. The short-term picture shows lots of ups and downs, but those short term losses do not change the fact that over the long term, the stock market has been a good place to invest.

We don't know how climate change will affect the frequency or intensity of El Niños and La Niñas, but the IPCC does expect that ENSO will continue to be an important influence on global climate through the 21st century.

4. Incorporating Climate Change in Regional Water Supply Planning

In February 2005, representatives from more than 20 cities, counties, tribes, state agencies, utility districts, and other organizations in the central Puget Sound (WA) region embarked on a voluntary effort to identify and compile information on key issues relevant to water supply planning in the region. The effort focused on seven topics areas, each of which was assigned a committee: water demand forecast, water supply assessment, climate change impacts, reclaimed water, tributary stream flows, source exchange strategies, and small water systems.

The Climate Change Technical Committee was tasked with assessing the impacts of climate change on water demand, water supplies, and instream flows. The project involved five phases.

• Phase 1 involved working with Committee members to understand and reach agreement on key aspects of climate change sciences and impacts as it related to the planning process.
• Phase 2 required developing daily temperature and precipitation data for 2025, 2050, and 2075 at select locations in the central Puget Sound region. The analysis used a combination of three different climate models and two different emissions scenarios (IPSL A2, GISS B1 and ECHAM5 A2).
• Phase 3 used the climate change scenarios developed in Phase 1 and a fine-scale hydrologic model to determine how climate change may affect daily streamflow at select locations, particularly inflows into reservoirs serving (or anticipated to serve) as major water supplies.
• Phase 4 required developing a framework that other technical committees could use to estimate the impacts of climate change on municipal water demand and water supply.
• Phase 5 provided a literature review of specific questions raised by the Committee about the possible impacts of climate change on cloud cover and groundwater.

Technical support to the Climate Change Committee was provided by the CIG and graduate students from the University of Washington's Department of Civil and Environmental Engineering.

The Climate Change Technical Committee completed its work in December 2007. A number of keystone products were developed for the effort which are now publicly available on the Internet. These key products include:

• Eight technical memoranda outlining the methodologies used to develop the meteorological and hydrologic climate change scenarios for the Climate Change Technical Committee;
• A white paper describing 13 fully-referenced climate change “building blocks” about the impacts of climate change on temperature, precipitation, snowpack and glaciers, streamflows, sea level rise, and salmon habitat and populations; and
• An online climate variables database for evaluating climate change impacts on water resources in King, Snohomish, and Pierce Counties. Products on the website include downloadable meteorological and hydrological data, graphs of projected changes in streamflows at 15 locations in the three-county area, and spatial plots displaying changes in climate over the entire region. All of the products generated by the database can be customized by the user according to climate model, climate parameters (e.g., temperature and precipitation), time step (daily vs. monthly), seasons, and years (e.g., 2000, 2025, 2050, and 2075), among others.

More information on the effort is available on the Climate Change Technical Committee and Regional Water Supply Planning web sites.

5. Recommendations for Adapting to Climate Change in Oregon Released

State-level adaptation planning in Oregon reached a milestone in January 2008 with the release of A Framework for Addressing Rapid Climate Change. The report, prepared by the Climate Change Integration Group, provides recommendations for addressing climate change in Oregon via preparation and adaptation, mitigation, outreach and education, and research. Framework recommendations include:

• taking immediate action to begin preparing for climate change;
• conducting localized climate change impacts assessments to determine how climate change will affect Oregon's diverse regions;
• modifying planning processes to take climate change mitigation and adaptation planning needs into account;
• developing and refining a climate change research agenda for Oregon; and
• developing and implementing a climate change mitigation and adaptation outreach program.

Oregon's recently established Global Warming Commission (GWC) will oversee implementation of the recommendations. The GWC is a 25 member commission representing the policy, science, education, and implementation aspects of reducing greenhouse gas emissions and adaptive planning.

Similar adaptation planning efforts are taking place in Washington State, as previously reported in the Climate CIGnal. Look for future updates on Oregon and Washington's adaptation efforts in the Climate CIGnal.

6. CIG Partnering in Massive Regional Modeling Project Using Volunteer Computing

CIG researchers Philip Mote, Eric Salathé, and postdoc Valérie Dulière have begun work on a research project that will perform thousands of regional modeling simulations using volunteer computers. The ensemble of climate model simulations made possible with volunteer computers is far larger than what would be accomplished with a modest in-house compute cluster and approaches the capacity of a dedicated supercomputer.

These results will allow CIG researchers to better understand uncertainties in climate projections and to better estimate changes in the statistics of extreme events. Issues to be studied in this project include several policy-relevant aspects of regional climate change for most of the western U.S., including extreme precipitation, windstorms, summer drought, and spring snowpack.

This project, funded by a Microsoft Corporation gift, is based on the successful Climateprediction.net (CPDN) framework developed for global climate studies. Collaborators include CPDN founder Myles Allen of Oxford University and Richard Jones of the United Kingdom's Hadley Centre for Climate Prediction and Research.

A public call for volunteers to run climate simulations for the PNW on their desktop PCs will be made sometime in winter 2008-09. Please stay tuned for details. For those interested in getting started now, global climate projects are already available at Climateprediction.net.

7. Portland and Seattle Join Water Utility Climate Alliance

Portland Water Bureau and Seattle Public Utilities joined with six other major U.S. water utilities in September 2007 to create the Water Utility Climate Alliance. The objectives of the Alliance are to:

• Improve and expand climate change research so water managers can consider the potential implications climatic changes may have on water resource planning;
• Promote and collaborate in the development of adaptation strategies and tools to reduce the impacts of rising temperature and changes in precipitation patterns on our infrastructure and water supplies; and
• Identify and minimize greenhouse gas emissions resulting from the operations of WUCA member agencies.

As a first step, the Alliance is calling for regional or local level application of improved climate models so that water utilities have accesses to consistent climate data. The Alliance has also called for coordinated research efforts and decision support tools related to abrupt climate change.

Other Alliance members include Denver Water, the Metropolitan Water District of Southern California, the New York City Department of Environmental Protection, the San Diego County Water Authority, and the Southern Nevada Water Authority. Collectively, the members of the Alliance provide water to more than 36 million people.

8. Professor Rick Palmer Takes New Position in Massachusetts

Professor Rick Palmer, a CIG principal and professor at the University of Washington's Department of Civil and Environmental Engineering, recently left the University of Washington to become Department Head and Professor for the Department of Civil and Environmental Engineering at the University of Massachusetts at Amherst.

Professor Palmer taught at the University of Washington for 28 years. During that time, Professor Palmer made significant research contributions in the areas of water supply planning, hydropower production, the use of computer models to aid in the negotiation of water conflicts, and the impacts of climate change on water resources, including climate change impacts studies for the Portland (OR) Water Bureau, the Seattle (WA) Public Utilities, the Tualatin (OR) River Basin, and the Central Puget Sound water supply planning effort described in this newsletter. We wish Professor Palmer the greatest success in his new position at the University of Massachusetts.

9. CIG in the News: Recent Media Stories

Recent media stories featuring CIG research and/or researchers include the following:

• UW plan merges forestry school, 5 others, The Seattle Times, May 15, 2008

• World's mountains will not remain water towers forever, Thaindian News, April 16, 2008

• Seattle's plans for future shaped by climate change still in infancy, The Seattle Post-Intelligencer, April 1, 2008

• Despite another cold winter in Oregon, global warming hasn't gone away, experts say, The Oregonian, March 20, 2008

• Studies warn area water will get more scarce, The Seattle Times, March 1, 2008

• Many factors contribute to this year's crazy snowfall, The Yakima Herald-Republic, February 9, 2008
• Floods and droughts: Water planners call for fundamental shift to deal with changing climate, Science Daily, February 5, 2008

Additional news items are available at CIG in the News.

10. Recent CIG Publications

Recent CIG publications include the following:

• Barnett, T., D.W. Pierce, H. Hidalgo, C. Bonfils, B.D. Santer, T. Das, G. Bala, A.W. Wood, T. Nazawa, A, Mirin, D. Cayan, and M. Dettinger. 2008. Human-induced changes in the hydrology of the western United States. Science Express Reports 10.1126/science.1152538.

• Crozier, L.G., A.P. Hendry, P.W. Lawson, T.P. Quinn, N.J. Mantua, J. Battin, R.G. Shaw, and R.B. Huey. 2008. Potential responses to climate change for organisms with complex life histories: Evolution and plasticity in Pacific salmon. Evolutionary Applications 2: 252–270, doi:10.1111/j.1752-4571.2008.00033.x.

• Crozier, L.G., R.W. Zabel, and A.F. Hamlet. 2008. Predicting differential effects of climate change at the population level with life-cycle models of spring Chinook salmon. Global Change Biology 14(2): 236–249, doi:10.1111/j.1365-2486.2007.01497.x.

• Heyerdahl, E.K., D. McKenzie, L. Daniels, A.E. Hessl, J.S. Littell, and N.J. Mantua. 2008. Climate drivers of regionally synchronous fires in the inland Northwest (1651-1900). International Journal of Wildland Fire 17:40-49.

• Milly, P.C.D., J. Betancourt, M. Falkenmark, R.M. Hirsch, Z.W. Kundzewicz, D.P. Lettenmaier, and R.J. Stouffer. 2008. Stationarity is dead: Whither water management?. Science 319 (5863): 573-574, DOI: 10.1126/science.1151915.

• Mote, P.W., A.F. Hamlet, and E.P. Salathé. 2008. Has spring snowpack declined in the Washington Cascades? Hydrology and Earth System Sciences 12: 193-206.

• National Research Council 2008. Research and Networks for Decision Support in the NOAA Sectoral Applications Research Program. Panel on Design Issues for the NOAA Sectoral Applications Research Program, H.M. Ingram and P.C. Stern (eds.), Committee on the Human Dimensions of Global Change, Division of Behavioral and Social Sciences and Education. The National Academies Press, Washington, DC. 84 pp.

• Shukla, S., and A.W. Wood. 2008. Use of a standardized runoff index for characterizing hydrologic drought. Geophysical Research Letters 35, L02405, doi:10.1029/2007GL032487.

• Wood, A.W. 2008. The University of Washington Surface Water Monitor: An experimental platform for national hydrologic assessment and prediction. In Proceedings of the AMS 22nd Conference on Hydrology, New Orleans, LA, January 20-24, 2008.

• Wood, A.W., and J.C. Schaake. 2008. Correcting errors in streamflow forecast ensemble mean and spread. Journal of Hydrometeorology 9(1): 132-148.

For copies of these papers, please contact the CIG. A complete listing of CIG publications is available on the CSES publications page.