Seasonal Forecasts using Objectively Chosen Analog Years

1. Seasonal Forecasts using Objectively Chosen Analog Years

4. 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 …

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.

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.

9. Climate Indices • 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 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)

13. 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

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 Forecast: Climate Division 2 – Willamette Valley Nov Dec Jan Feb Mar Apr Above Near Near Below Near Below Temp: Near Near Above Near Below Near Precip:

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

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

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

22. On to Next Winter…

23. On to Next Winter…

24. 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…