1. Drought in the West: Short-Range Forecasts to Assist with Local and Regional Planning Douglas Le Comte NOAA/CPC Association of Bay Area Governments: Water/Land Use Collaboration August 7, 2008

2. Outline Current Drought SituationCurrent Drought Situation Medium Range and Seasonal ForecastsMedium Range and Seasonal Forecasts Historical PerspectiveHistorical Perspective Climate ChangeClimate Change Dust Event Honda Proving Center June 4 2008 Cantil CA

3. Water Year Precipitation http://www.hprcc.unl.edu/maps/current / http://www.calclim.dri.edu/anommaps.html California Climate Data Archive High Plains Regional Climate Center

4. Wet Winter…Dry Spring http://www.cpc.ncep.noaa.gov/products/global_monitoring/precipitation/global_precip_accum.shtml

5. Recent U.S. Drought Monitor

6. Western Snowpack 2008 vs 2007 http://www.wcc.nrcs.usda.gov/snowcourse/snow_map.html

7. Western Streamflow Forecasts http://www.wcc.nrcs.usda.gov/cgibin/sssf.pl

8. California Drought Summary (from Dep’t of Water Resources Executive Summary) Water Year precipitation = 85% of averageWater Year precipitation = 85% of average Runoff = 60% of averageRunoff = 60% of average Reservoirs = 75% of averageReservoirs = 75% of average For Northern Sierra, March-June = driest since records began in 1921 (3.4 in)For Northern Sierra, March-June = driest since records began in 1921 (3.4 in) http://cdec.water.ca.gov/cgi-progs/reports/EXECSUM

9. Two Looks at the Current Drought: How Bad? Multimodel Soil Moisture Percentiles (83 years of data) Aug. 3, 2008 Palmer Hydro Drought Index Arguably, the 4 th “worst” drought since 1900! http://www.ncdc.noaa.gov/oa/climate/research/prelim/drought/state-reg-moisture-status.html

10. Historical Drought: River Runoff since 1900 http://meteora.ucsd.edu/cap/pdffiles/DroughtReport2008.pdf

11. The Seasonal Drought Outlook http://www.cpc.ncep.noaa.gov/products/expert_assessment/seasonal_drought.html

12. Web Resources for Drought and Forecasts Climate Prediction Center for Medium and Long Range Forecasts:Climate Prediction Center for Medium and Long Range Forecasts: www.cpc.ncep.noaa.gov National Integrated Drought Informaton System for the new drought portal: www.drought.govNational Integrated Drought Informaton System for the new drought portal: www.drought.gov California Applications Program and the California Climate Change Center: http://meteora.ucsd.edu/cap/California Applications Program and the California Climate Change Center: http://meteora.ucsd.edu/cap/http://meteora.ucsd.edu/cap/ California Climate Tracker: http://www.wrcc.dri.edu/monitor/cal- mon/index.htmlCalifornia Climate Tracker: http://www.wrcc.dri.edu/monitor/cal- mon/index.html Drought Impact Reporter droughtreporter.unl.edu CPC NIDIS

13. ENSO (El Nino-Southern Oscillation) Status: Neutral http://www.cpc.ncep.noaa.gov/ Thru Aug 3, 2008 http://www.bom.gov.au/climate/enso/indices.shtml La Nina last winter

14. El Nino and La Nina Winter (Jan-Mar) Precipitation El Nino La Nina Frequency of occurrence

15. A majority of ENSO forecasts indicate ENSO-neutral conditions through Northern Hemisphere spring 2009. Pacific Niño 3.4 SST Outlook Figure provided by the International Research Institute (IRI) for Climate and Society (updated 15 July 2008).

16. 6-10 Day and 8-14 Day Rainfall http://www.cpc.ncep.noaa.gov/products/forecasts /

17. CPC Seasonal Precipitation Forecasts http://www.cpc.ncep.noaa.gov/products/predictions/90day / ASO SON ONDNDJ

18. CPC Winter Outlook DJF DJFJFM

19. Experimental University of Washington Forecasts http://www.hydro.washington.edu/forecast/monitor/outlook/index.shtml Current Runoff Forecast for Oct. 26, 2008 (Based on historical data) Improvement Tendency for improvement based on this experimental forecast.

20. Palmer Drought Probabilities to October 2008 Courtesy R. Tinker, CPC

21. Climate Division (C.D.) C. D. Name July 2008 PHDI July 2008 PHDI Percentile July 2008 Nominal Drought Monitor (D. M.) Equivalent Like-Cases Chance for 1+ D. M. Equivalent Improvement by March 2009 Like-Cases Chance for March 2009 PHDI > 30 th Percentile (D0+ D.M. Equiv.) CA01 North Coast -2.578.8D272%67% CA02Sacramento-3.630.0D460%40% CA03 Northeast Interior -2.3622.6D036%46% CA04 Central Coast -2.2918.1D170%70% CA05 San Joaquin -3.993.2D390%50% CA06 South Coast -3.488.8D253%42% CA07 Southeast Desert -3.3815.9D160%60% Palmer Hydrologic Drought Index (PHDI) Statistics for California Climate Divisions for California Climate Divisions Potential March 2009 Conditions Based on July 2008 Conditions & July-March Changes Following Past July’s with Similar Conditions Good odds for (Palmer) drought ending coastal areas next winter

22. CFS* Model Winter Forecast Probability of Anomalous Precipitation (as of Aug. 5) http://www.cpc.ncep.noaa.gov/products/analysis_monitoring/lanina/ensoforecast.shtml Tilt toward below normal in CA and the SW *Coupled (or Climate) Forecast System Bottom line: History suggests significant relief unlikely before December, and forecasts for next winter are ambivalent, but some dynamic models are tilting dry.

23. Climate Model Forecasts:Precipitation California Climate Change Center http://meteora.ucsd.edu/cap/cat2008_peak.html Precipitation forecast uncertain for next few decades

24. California Climate Model Forecasts: Temperature Temperatures should keep going up

25. Projected Annual Runoff 2041-2060 Less runoff for California and the Southwest

26. “Prediction is very difficult, especially about the future” Niels Bohr, Danish physicist (not Yogi Berra)