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

4. Best Prediction Since 1996

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

6. February 6, 2011

7. Back to the Weather!

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

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

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

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

12. January 2011 ( Forecast Issued October 16, 2010) Forecast Precipitation Actual Precipitation Data courtesy of the National Climatic Data Center (NCDC)

13. January 2011 ( Forecast Issued October 16, 2010) Forecast Temperatures Actual Temperatures Data courtesy of the National Climatic Data Center (NCDC)

14. February 2011 ( Forecast Issued October 16, 2010) Forecast Precipitation Actual Precipitation Data courtesy of the National Climatic Data Center (NCDC)

15. February 2011 ( Forecast Issued October 16, 2010) Forecast Temperatures Actual Temperatures Data courtesy of the National Climatic Data Center (NCDC)

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

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

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

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

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

21. Typical ENSO Patterns

22. WarmEvent ColdEvent

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

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

25. La Niña Events El Niño Events

26. RepeatingPattern?

27. (2007-08; 1998-99; 1988-89; 1973-74; 1970-71) 1st Year2nd Year

28. ONI Based on SST Departures in Niño 3.4

29. La Niña Events El Niño Events

30. ONI Based on SST Departures in Niño 3.4 RepeatingPattern?

31. 1st Year2nd Year (2007-08; 1998-99; 1988-89; 1973-74; 2070-71)

32. El Niño Modoki Feb. 2010

33. La Niña Feb. 2011

34. ENSO-Neutral July 2011

35. August - October, 2011

36. La Niña Oct. 2011

37. ENSO-Neutral Oct. 2008

38. La Niña Returned? Dec. 2008

39. La Niña Oct. 2011

40. Winter Forecast 2011-12

42. November 2011 Forecast PrecipitationTemperatures

43. November 2011 Forecast (Based on 1971, 1974, 1989, 1999, & 2008) Above to well above average temperatures. Above to well above average temperatures. Precipitation will most likely be near or slightly below normal statewide. Precipitation will most likely be near or slightly below normal statewide. Expect minimal mountain snow before the final week of the month. Expect minimal mountain snow before the final week of the month.

44. December 2011 Forecast PrecipitationTemperatures

45. December 2011 Forecast (Based on 1971, 1974, 1989, 1999, & 2008) Confidence in the December forecast is below average, due to large variations in weather conditions during the analog years. Confidence in the December forecast is below average, due to large variations in weather conditions during the analog years. Extreme weather conditions are possible. Extreme weather conditions are possible. The average of the analog years would suggest slightly above average temperatures and slightly below average precipitation. The average of the analog years would suggest slightly above average temperatures and slightly below average precipitation.

46. January 2012 Forecast PrecipitationTemperatures

47. January 2012 Forecast (Based on 1972, 1975, 1990, 2000, & 2009) The analog years are consistent in showing a switch to above normal precipitation. The analog years are consistent in showing a switch to above normal precipitation. Analog years do not yield a consistent temperature forecast...a blend would suggest near to slightly below normal temperatures west and above normal east. Analog years do not yield a consistent temperature forecast...a blend would suggest near to slightly below normal temperatures west and above normal east. Significant mountain snow likely with a good chance of a late-month Arctic event. Significant mountain snow likely with a good chance of a late-month Arctic event.

48. February 2012 Forecast PrecipitationTemperatures

49. February 2012 Forecast (Based on 1972, 1975, 1990, 2000, & 2009) Near to above normal precipitation. Near to above normal precipitation. Below normal temperatures. Below normal temperatures. Significant mountain snow likely with an above average snowpack for most areas. Significant mountain snow likely with an above average snowpack for most areas. Good chance that the month will begin with a cold outbreak along with some valley snow or freezing rain. Good chance that the month will begin with a cold outbreak along with some valley snow or freezing rain.

50. November - January 2011-12 Forecast PrecipitationTemperatures

51. PrecipitationTemperatures

52. December - February 2011-12 Forecast PrecipitationTemperatures

53. PrecipitationTemperatures

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

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

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

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