1. Seasonal Forecasts using Objectively Chosen Analog Years Seasonal Forecasts using Objectively Chosen Analog Years

4. Seasonal Forecasts using Objectively Chosen Analog Years Seasonal Forecasts using Objectively Chosen Analog Years The Technique 2011-12 Verification Analogs for Upcoming Winter The Forecast

5. Analog Seasonal Forecasting Look at this year so far…

6. Analog Seasonal Forecasting Look at this year so far… Look for past years that are similar to this year … Look at this year so far… Look for past years that are similar to this year …

7. Analog Seasonal Forecasting Look at this year so far… Look for past years that are similar to this year … Use what subsequently happened in those past years as a forecast for what will happen this year. Look at this year so far… Look for past years that are similar to this year … Use what subsequently happened in those past years as a forecast for what will happen this year.

8. Analog Seasonal Forecasting Look at this year so far… Look for past years that are similar to this year … Use what subsequently happened in those past years as a forecast for what will happen this year. Look at this year so far… Look for past years that are similar to this year … Use what subsequently happened in those past years as a forecast for what will happen this year.

9. Climate Indices PNA (Pacific North American Index) NAO (North Atlantic Oscillation) Jones NAO EPO (Eastern Pacific Oscillation) TNH ONI NTA (North Tropical Atlantic Index) CAR (Caribbean Index) MEI BEST Nino 3 Nino 1+2 Nino 3+4 Nino 4 Pacific Warm Pool Tropical Pacific SST EOF TNA TSA WHWP WP (West Pacific Index) QBO (Quasi-Biennial Oscillation) PDO (Pacific Decadal Oscillation) PMM (Pacific Meridional Mode) NP (North Pacific Index) PNA (Pacific North American Index) NAO (North Atlantic Oscillation) Jones NAO EPO (Eastern Pacific Oscillation) TNH ONI NTA (North Tropical Atlantic Index) CAR (Caribbean Index) MEI BEST Nino 3 Nino 1+2 Nino 3+4 Nino 4 Pacific Warm Pool Tropical Pacific SST EOF TNA TSA WHWP WP (West Pacific Index) QBO (Quasi-Biennial Oscillation) PDO (Pacific Decadal Oscillation) PMM (Pacific Meridional Mode) NP (North Pacific Index) NOI (Northern Oscillation Index) AO (Arctic Oscillation) AAO TNI Atlantic Tripole SST EOF AMO AMM (Atlantic Meridional Mode) ACE (Atlantic Accumulated Cyclone Intensities) Solar Cycle (Flux) Monthly Hurricane Total MDR Hurricanes SST Anomaly MDR - Tropics SST Anomaly Central India Monsoon Precipitation Sahel Rainfall Brazil Rainfall SW USA Monsoon Global Mean Temperature ESPI Globally integrated angular momentum NOI (Northern Oscillation Index) AO (Arctic Oscillation) AAO TNI Atlantic Tripole SST EOF AMO AMM (Atlantic Meridional Mode) ACE (Atlantic Accumulated Cyclone Intensities) Solar Cycle (Flux) Monthly Hurricane Total MDR Hurricanes SST Anomaly MDR - Tropics SST Anomaly Central India Monsoon Precipitation Sahel Rainfall Brazil Rainfall SW USA Monsoon Global Mean Temperature ESPI Globally integrated angular momentum

13. Not just the index… But sensible weather… IE Warm/Cool… Wet/Dry Not just the index… But sensible weather… IE Warm/Cool… Wet/Dry

14. Not just the index… But sensible weather… IE Warm/Cool… Wet/Dry Not just the index… But sensible weather… IE Warm/Cool… Wet/Dry

15. Automate the Process Compare each previous year to this year… Compute a “Goodness of Fit” number… Sort “Goodness of Fit”… Print/Save results… Do this for multiple indices… Find “Consensus” analog years

17. Last Year’s

18. 2011/12 Forecast Summary Climate Division 2 – Willamette Valley Nov Dec Jan Feb Mar Apr Temp: Precip: Above Near Near Below Near Below Near Near Above Near Below Near Forecast:

19. 2011/12 Forecast Summary Climate Division 2 – Willamette Valley Nov Dec Jan Feb Mar Apr Temp: Precip: Above Near Near Below Near Below Near Near Above Near Below Near Forecast: Climate Division 2 – Willamette Valley Nov Dec Jan Feb Mar Apr Temp: Precip: Near Below Above Below Above Above Observed: Below Below Near Near Below Below

20. 2011/12 Forecast Summary Climate Division 2 – Willamette Valley Nov Dec Jan Feb Mar Apr Temp: Precip: Above Near Near Below Near Below Near Near Above Near Below Near Forecast: Climate Division 2 – Willamette Valley Nov Dec Jan Feb Mar Apr Temp: Precip: Near Below Above Below Above Above Observed: Below Below Near Near Below Below    

21. 2011/12 Verification 4 “Hits” 6 One-category errors 2 Two-category errors

22. On to Next Winter…

25. Indices CPC SOI, MEI, ONI, BOM SOI, Nino 3.4 Anom, Nino 3 Temps, Nino 4 Temps, PNA, PDO, NAO, AO, WP, and the QBO.

27. Composites December…

33. Composites January…

39. Composites February…

45. Composites March…

51. April May

53. http://weather.jimlittle.net/2012 Winter Forecast Graphics

54. Portland/Willamette Valley Month by Month…

63. Median

64. Median “Near”

71. Summary Climate Division 2 – Willamette Valley Dec Jan Feb Mar Apr May Temp: Precip: Near Near Above Near Near Near Below Above Below Near Above Near

72. Cascades

73. Summary Climate Division 4 – North Cascades Dec Jan Feb Mar Apr May Temp: Precip: Near Near Near Near Below Near Near Above Below Above Above Below

74. 23d24th25th26th27th28th29th30th31st 2009 21 2019 26 2001 56 545250 48 1996 53656467 68715250 1986 688876611 1968 545546 5260657074 1963 878986653 Government Camp Snow December Snow Depth in Inches

75. 23d24th25th26th27th28th29th30th31st 2009 21 2019 26 2001 56 545250 48 1996 53656467 68715250 1986 688876611 1968 545546 5260657074 1963 878986653 Government Camp Snow December Snow Depth in Inches

76. 23d24th25th26th27th28th29th30th31st 2009 21 2019 26 2001 56 545250 48 1996 53656467 68715250 1986 688876611 1968 545546 5260657074 1963 878986653 Government Camp Snow December Snow Depth in Inches 4 of 6 Years Great! 2 of 6 Marginal

77. Questions? Climate Division 2 – Willamette Valley Dec Jan Feb Mar Apr May Temp: Precip: Near Near Above Near Near Near Below Above Below Near Above Near jim@mail.wxnorthwest.com jlittle@odf.state.or.us http://weather.jimlittle.net/2012 Winter Forecast Graphics