1 Climate recap and outlook Nate Mantua, PhD University of Washington Center for Science in the Earth System - Climate Impacts Group Kelso, WA October 3, 2006 Nate Mantua, PhD University of Washington Center for Science in the Earth System - Climate Impacts Group Kelso, WA October 3, 2006

The CSES - Climate Impacts Group Goal: help the Pacific Northwest become more resilient to climate variations and climate change Supported by NOAA Climate Program Office as part of the Regional Integrated Science and Assessments (RISA) program Goal: help the Pacific Northwest become more resilient to climate variations and climate change Supported by NOAA Climate Program Office as part of the Regional Integrated Science and Assessments (RISA) program

3 global temperatures continue to run high

4 The pattern is global

5 Current drought

7 Accumulated Precip for the past year Source: html

8 Accumulated Precip for the past year Source: html

9 Accumulated Precip for the past year Source: html

10 Accumulated Precip for the past year Source: html

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12 Daily Temperatures +0.90ºC+0.81ºC

snow pack Warm weather in May started a rapid melt of the PNWs abundant snow pack

14 Our hot-dry summer For OR-ID-WA, May-June-July 2006 was warmest on record (back to 1895) June-July- August was 3rd warmest on record For OR-ID-WA, May-June-July 2006 was warmest on record (back to 1895) June-July- August was 3rd warmest on record

15 28-day mean stream flow from the USGS

16 Oct 1st estimated soil moisture percentiles Courtesy of Andy Wood, University of Washington, data and images are available at on.edu/forecast/monitor Courtesy of Andy Wood, University of Washington, data and images are available at on.edu/forecast/monitor

17 Last year’s outlook The ENSO outlook: La Nada (“normal”) PNW climate outlook: odds favoring a “warm” winter and spring The ENSO outlook: La Nada (“normal”) PNW climate outlook: odds favoring a “warm” winter and spring

18 IRI ENSO Forecast Summary Forecasts from October 2005 called for Nino34 ranging from -0.2 to +0.6, with an average of ~ O/currentinfo/SST_table.html#figur e

19 Oct 12, 2005 NOAA NCEP ENSO forecasts

20 Nov-Mar 2006 SST anomalies: a mild La Niña for the Pacific

21 Last year’s forecast (from Oct 20) DJF temp FMA temp 2006

22 Last year’s precipitation forecasts for : issued Oct

23 The forecast Cartoon obtained from: Cartoon obtained from: Forecasts … ?

24 Global Ocean Surface Temperatures: July 2-September

25 The tropical ocean is warm

26 El Niño is simmering Tropical ocean temperatures have been warmer than average since mid- May, and have already crossed the “El Niño” threshold

27 The latest ENSO forecasts See European Center NOAA NCEP Forecast summaries

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29 Average El Niño winter precip: Dry on the western, wetter slopes, slightly wet or near average for the “rainshadow” areas From Dry on the western, wetter slopes, slightly wet or near average for the “rainshadow” areas From

30 Pacific Ocean Outlook Summary Current forecasts rate weak-to-moderate El Niño as most likely situation for 2006/07 PDO: A simple forecast with skill relies on “PDO persistence + ENSO influence” ( see Newman et al. (2003), J. Climate ) Expect weak warm phase PDO conditions for 2006/7 PDO = +0.3 to +0.8 st devs for Nino34 = +0.5 to +1.5 A Note on Last year… Current forecasts rate weak-to-moderate El Niño as most likely situation for 2006/07 PDO: A simple forecast with skill relies on “PDO persistence + ENSO influence” ( see Newman et al. (2003), J. Climate ) Expect weak warm phase PDO conditions for 2006/7 PDO = +0.3 to +0.8 st devs for Nino34 = +0.5 to +1.5 A Note on Last year… (July-June averages) ForecastObserved Nino3.4 index-0.2 to PDO index+0.2 to

NOAA/CPC forecasts issued September 21, 2006 OND precip JFM precip

32 NOAA/CPC forecasts issued September 21, 2006 OND temperature JFM temperature

33 The Bottom line a weak to moderate El Niño is likely for the next 2-3 seasons because of trends and expectations for a weak to moderate intensity El Niño, above- average fall/winter/spring temperatures are likely El Niño also tilts the odds in favor of a dry fall/winter and below average end-of- season snow pack a weak to moderate El Niño is likely for the next 2-3 seasons because of trends and expectations for a weak to moderate intensity El Niño, above- average fall/winter/spring temperatures are likely El Niño also tilts the odds in favor of a dry fall/winter and below average end-of- season snow pack See