1. U.S Drought Highlights Since October 2004 Douglas Le Comte NOAA/CPC 30 th Annual Climate Diagnostics and Prediction Workshop October 24-28, 2005

2. Outline Drought Highlights —Southwest Alleviation, Northwest Development, and Midwest Summer DevelopmentDrought Highlights —Southwest Alleviation, Northwest Development, and Midwest Summer Development Drought Forecasts —How are we doing?Drought Forecasts —How are we doing?

3. What A Difference A Season Made in the West!

4. October vs April Drought

5. Water Year Precipitation

6. Snow Water Content April 2005

7. Impressive Snowpack on Snowbird November 7, 2004 A pretty good omen that the 2004-05 snow season would be extraordinary!

8. WETTER WARMER SSTs Although El Nino’s are generally associated with improved drought conditions in the U.S. Southwest, this is by no means assured. The best odds for improvement come with stronger events (SST anomalies over +1.5 deg. C). EL NINO’S and SOUTHWESTERN DROUGHT Expected range of SSTs

9. Streamflow Forecasts April 1, 2005

10. Spring-Summer Changes

11. April vs July 2005

12. Changes to October 4, 2005

13. August vs October 2005

14. October 4 vs October 11 2005

15. The Seasonal Drought Outlooks

16. Selected Drought Outlook Tools 2-Week Soil Moisture2-Week Soil Moisture Seasonal Constructed Analog Soil ForecastsSeasonal Constructed Analog Soil Forecasts NCDC Palmer Drought Amelioration Probability MapsNCDC Palmer Drought Amelioration Probability Maps

17. CPC 2-Wk Soil Moisture Forecast http://www.cpc.ncep.noaa.gov/soilmst/cas.shtml

18. Constructed Analog Soil Moisture USA http://www.cpc.ncep.noaa.gov/soilmst/cas.shtml Observed Forecast

19. NCDC Drought Amelioration Probabilities

20. How Are We Doing?

21. How Did We Do With the Western Drought? Too cautious in September! Finally got it right in Dec!

22. Time Series of Verification Scores Mean Pct Correct 59% Mean Persistence Score 45%

23. Selected Future Improvements Better seasonal temp/precip forecasts thanks to new consolidation toolBetter seasonal temp/precip forecasts thanks to new consolidation tool Better seasonal soil moisture forecasts from NLDAS projects (Univ. of WA, Princeton, NCEP)Better seasonal soil moisture forecasts from NLDAS projects (Univ. of WA, Princeton, NCEP) Research leading to improved understanding of the underlying causes of drought (e.g., air-sea and ground-air interactions)Research leading to improved understanding of the underlying causes of drought (e.g., air-sea and ground-air interactions)

24. Parting Wisdom “If you’re going to predict, predict often. As long as you keep updating your prediction, people forget your last prediction.”“If you’re going to predict, predict often. As long as you keep updating your prediction, people forget your last prediction.” Milton Friedman