Winter Forecast 2011-12 October 29, 2011

1. Winter Forecast 2011-12 October 29, 2011 PWODT/OMSI Exclusive Presentation! oregon.gov/oda/nrd/weather.shtml#weather_forecasts Pete Parsons, ODF Meteorologist 503-945-7448 pparsons@odf.state.or.us

4. Best Prediction Since 1996

5. Winter Prediction 2010-11… • Packers will overcome injuries and win the Super Bowl!

6. February 6, 2011

7. Back to the Weather!

8. November – January 2010-11(Forecast Issued October 16, 2010) Forecast Precipitation Actual Precipitation Data courtesy of the National Climatic Data Center (NCDC)

9. November – January 2010-11(Forecast Issued October 16, 2010) Forecast Temperatures Actual Temperatures Data courtesy of the National Climatic Data Center (NCDC)

10. December – February 2010-11(Forecast Issued October 16, 2010) Forecast Precipitation Actual Precipitation Data courtesy of the National Climatic Data Center (NCDC)

11. December – February 2010-11(Forecast Issued October 16, 2010) Forecast Temperatures Actual Temperatures Data courtesy of the National Climatic Data Center (NCDC)

12. Winter 2010-11 Forecast • Well above normal precipitation. • Near normal temperatures. • Above average mountain snow. • One or more of the following in December and/or January: coastal windstorm(s); Arctic outbreak; valley snow/ice; flooding.

13. Typical ENSO Patterns

14. Warm Event Cold Event

15. PWODT Seasonal Climate Forecasting Method Use the SOI and ONI to Identify Past Years With Similar Tropical Pacific Ocean Sea-Surface Temperatures. Use Historical Data From Those Years to Make General Seasonal Predictions. No Corrections are Made for Changes in Global Climate…Creating Error.

16. SOI Based On Pressure Anomalies of Two Sites Darwin Tahiti

17. La Niña Events El Niño Events

18. Repeating Pattern?

19. ONI Based on SST Departures in Niño 3.4

20. ONI Based on SST Departures in Niño 3.4 El Niño Events La Niña Events

21. ONI Based on SST Departures in Niño 3.4 Repeating Pattern?

22. El Niño Modoki Feb. 2010

23. La Niña Feb. 2011

24. ENSO-Neutral July 2011

25. August - October, 2011

26. La Niña Oct. 2011

27. ENSO-Neutral Oct. 2008

28. La Niña Returned? Dec. 2008

29. La Niña Oct. 2011

30. Winter Forecast 2011-12

31. November - January2011-12 Forecast Precipitation Temperatures

32. December - February2011-12 Forecast Precipitation Temperatures

33. Winter 2011-12 Forecast • Above average temperatures early. Bonus if ski areas can open by Thanksgiving. • Turning stormy in December and January with another cold February. • Cold periods will have a better chance of being accompanied by snow this winter. • Most mountain snowpacks should be above normal by late January - February.

34. Winter 2011-12 Snowlights • Average Portland snowfall 4.5” • Analog average snowfall 7.5” • Above average snowfall likely for the Willamette Valley. • Watch out for freezing rain.

35. Winter’s Big Question? Or Worse…? Could We See a Repeat of 2008-09?

37. Winter Forecast 2011-12 October 29, 2011 PWODT/OMSI Exclusive Presentation! oregon.gov/oda/nrd/weather.shtml#weather_forecasts Pete Parsons, ODF Meteorologist 503-945-7448 pparsons@odf.state.or.us