1. Three Types of Drought in the Pacific Northwest – 2001, 2003, & 2005 Karin Bumbaco Philip Mote Office of the Washington State Climatologist University of Washington March 21, 2009 1

2. What is drought? “insufficient water to meet needs” (Redmond, 2002) Defined in terms of its impacts Difficult to quantify 2 1999-2008 water years compared to 1950-1995 normal Composite % of normal precipitation

3. Methods Yearly total precipitation and average temperature were ranked (1895-2005) for DJF and JJA for WA and OR Monthly average streamflow data at 216 gauges in WA and OR (55 years) were also ranked relative to 2001 and 2003 3

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7. 2001 November to March had below average precipitation leading to low snowpack 2 nd driest DJF 7

8. 2001 Record low precipitation in Portland, Astoria, Corvallis, and Eugene for the water year – 41-67% of normal Driest water year in Hoquiam and Vancouver, 2 nd driest in Spokane, 4 th driest in Seattle 8 WA OR

9. Rank of 2001 DJF streamflow with 55 yrs Low streamflow in western WA and OR (many ranking 2 nd to 1977) 9 Fig: Rob Norheim

10. 2001 Impacts – Agricultural Drought Pro-ratable junior water users in Yakima Basin, WA only received 37% of their entitlement – $130 million loss in agriculture revenues Klamath Basin, OR had a showdown over water – Suckerfish vs. irrigated water for farmers – $157 million loss in agriculture revenues Low river flows resulted in 5,300 MW loss in hydropower in WA ($3.5 billion) 10

11. 2003 May through Sept had below average precipitation 4 th warmest DJF – low snowpack in OR 2 nd warmest and driest JJA 11

12. 2003 Impacts 12 2003 JJA flows low in western WA and OR Many forest fires in OR – Booth and Bear Butte fire – 3.7 million square meters – State of emergency Fig: Rob Norheim

13. 2005 - WA DJF Precipitation was below normal (70-80%) Snowpack was 20% of normal for the winter 13

14. 2005 Impacts - WA Snowmelt-dominated streams were low Drought declared March 10, 2005 – Hurt horticulture industry (lost 8-20% revenue in western WA) Ski areas lost 1 million visitors (69% of average 10 yr visitation) = $43 million 14

15. 2005 - OR More serious precipitation deficit in OR limiting snowpack like 2001 “Drought plan” was implemented in Klamath Basin in March 2005 – Limited water to 2 nd and 3 rd priority holders (e.g. city parks) Rains in March and April eased the burden 15

16. Relation to ENSO and PDO? 2001 had cold ENSO, cold PDO, and dry Southwest – Indian Ocean warmth in 1999-2002 was associated with drought in large area of mid- latitudes including the PNW (Hoerling and Kumar, 2003) – Warmer Indian Ocean could be responsible for drought in recent years 16

17. Summary Some droughts form in winter by low precipitation (2001) or a combination of low precipitation and high temperatures (2005) producing low snowpack – Impacts can be anticipated in most cases Some form unexpectedly in summer (2003) – Points to the need for better timely information in summer Implications for climate change 17

18. Thanks! Questions? 18