1. User meeting 14-16 June 20061 Monthly and Seasonal forecasts Laura Ferranti and the Seasonal Forecast Section User meeting 14-16 June 2006

2. 2 Outline: Monthly Forecast: -Performance -Verification information is available on web - New products are made available on the web Seasonal forecast: - Performance - EUROSIP multi-model products in progress - S3 verification/documentation in progress

3. User meeting 14-16 June 20063 Performance over the Northern Extra-tropics Monthly Forecast Persistence of day 5-11 ROC area of probability of 2-meter temperature in upper tercile Day 12-18 Day 19-32 Monthly Forecast Persistence of day 5-18

4. User meeting 14-16 June 20064 Monthly Forecast verification site: -

5. User meeting 14-16 June 20065 Examples of verification Example of probabilistic scores: ROC Map

6. User meeting 14-16 June 20066 Example of verification: Extreme cold over Russia

7. User meeting 14-16 June 20067 Cold event over Europe

8. User meeting 14-16 June 20068 Precipitation over India 08/05-15/0515/05-22/0522/05-29/0529/05-05/06 An. Day 5-11 Day 12-18

9. User meeting 14-16 June 20069 Indian monsoon Probability of precipitation in the upper tercile 27 real-time cases covering the period May-June-July-August 2002, 2003, 2004, 2005 ROC score: 0.64 0.49 DAY 12-18 DAY 19-25DAY 26-32 ROC score: 0.58 0.49ROC score: 0.46 0.48 Monthly Forecast Persistence of the probabilities of the previous week

10. User meeting 14-16 June 200610 Precipitation over Africa 08/05-15/0515/05-22/0522/05-29/0529/05-05/06 An. Day 5-11 Day 12-18

11. User meeting 14-16 June 200611 African monsoon Probability of precipitation in the upper tercile 27 real-time cases covering the period May-June-July-August 2002, 2003, 2004 and 2005 ROC score: 0.59 0.54 DAY 12-18DAY 19-25DAY 26-32 ROC score: 0.54 0.49ROC score: 0.53 0.49 Monthly Forecast Persistence of the probabilities of the previous week 20W-25E, 0N-20N

12. User meeting 14-16 June 200612 Indian Ocean Maritime continent western Pacific West. Hemis And Africa MJO real-time forecast

13. User meeting 14-16 June 200613 Stamp map of velocity potential at 200 hPa MJO real-time forecast

14. User meeting 14-16 June 200614 Nino3.4 Performance

15. User meeting 14-16 June 200615 Performance during the most recent La Niña event

16. User meeting 14-16 June 200616 Seasonal forecasting of tropical storms Forecasts starting on 1 st June 2005: JASON ECMWF EUROSIP OBS: JJASON 2005 WNPENPAtl

17. User meeting 14-16 June 200617 Seasonal forecasting of tropical storms 1993-2005 Forecasts issued in June ECMWF: corr 0.70 EUROSIP: corr 0.75

18. User meeting 14-16 June 200618 Observed anomalies SST: JJA 2005 EUROSIP: Forecast start May 2005

19. User meeting 14-16 June 200619 GPCP anomaly JJA 2005 Past performance (i):

20. User meeting 14-16 June 200620 EUROSIP predictions for DJF 2006 over Europe: Prob (mslp > median) Forecast started Nov 2005: observed anomaly: 2m temp mslp Prob (2m temp > median)

21. User meeting 14-16 June 200621 Ecmwf predictions for DJF 2006 over Europe: Forecast started Nov 2005: observed anomaly: 2m temp mslp Prob (2m temp > median) Prob (mslp < median)

22. User meeting 14-16 June 200622 Precipitation predictions for DJF 2006 over Europe: GPCP anomaly: Prob (precip > median) EUROSIP Forecast started Nov 2005: ECMWF

23. User meeting 14-16 June 200623 Seasonal forecast skill:

24. User meeting 14-16 June 200624 Seasonal forecast skill:

25. User meeting 14-16 June 200625 Skill comparison: S2 vs S3: S3 Operational (S2) Persistence

26. User meeting 14-16 June 200626 Summary (1): Monthly Forecast: Good performance over the Northern extra-tropics up to 19-32 days. Good skill in predicting the Indian monsoon. Prediction of the West African monsoon show less skill. Verification is on the website and it is updated every week. Additional products are made available on the web.

27. User meeting 14-16 June 200627 Summary (2): Seasonal Forecast: Good performance for the predictions of SST anomalies over the equatorial Pacific. Tropical storm predictions show a good skill and this is enhanced by the EUROSIP multi-model system. Neither the ECMWF or EUROSIP dynamical systems produced good predictions for the last winter (DJF 2005/06). The skill of the seasonal forecast varies with regions and seasons. Latest results from S3 indicate that the Niño predictions are generally improved.

28. User meeting 14-16 June 200628 Skill comparison: S3 vs S2 Operational SystemPrototype of the new system (S3) Blue is good, yellow is bad But based on 15 years, sampling error is substantial for local values, so spatial distribution is unreliable except where skill is high Preliminary results:

29. User meeting 14-16 June 200629 Seasonal forecasting of tropical storms Forecasts starting on 1 st June 2005: JASON ECMWF Met Office Meteo-FranceMultimodel OBS: JJASON 2005 WNP ENP Atl

30. User meeting 14-16 June 200630 Seasonal forecasting of tropical storms 1993-2005 Forecasts issued in June ECMWF: corr 0.70UKMO: corr 0.78 MetFr: corr 0.62 ECMWF: corr 0.75

31. User meeting 14-16 June 200631 Probability of 2m Temp > upper tercile of the model climate for JJA 2005 Forecasts start 1 May 2005 Eurosip ECMWF

32. User meeting 14-16 June 200632 Past performance: Guinea Coast precipitation from May 2005 forecasts Met Office Ecmwf Météo France

33. User meeting 14-16 June 200633 SST DJF 2006 Ecmwf Met Office Météo France

34. User meeting 14-16 June 200634 2m temp predictions for DJF 2006: i.c. Nov 05 ECMWF Met Office Météo France Observed anomalies

35. User meeting 14-16 June 200635 mslp predictions for DJF 2006: i.c. Nov 05 Met Office ECMWF Météo France Observed anomalies

36. User meeting 14-16 June 200636 Predictions of 2m temp anomalies over Southern Europe: Ecmwf Met Office Météo France

37. User meeting 14-16 June 200637 NAO Predictions : Météo France Met Office Ecmwf

38. User meeting 14-16 June 200638 DJF Correlation between: 2m temp over (0-35E,10-30N) and Z 500hPa (1987-2003) Met Office Ecmwf Era 40

39. User meeting 14-16 June 200639 Met Office Ecmwf Era 40 DJF Correlation between: 2m temp over (0-35E,10-30N) SST (1987-2003)

40. User meeting 14-16 June 200640 PERFORMANCE DAY 12-18 MAM 2006 Probability of 2-meter temperature in the upper tercile ROC score: 0.70 0.62 Northern ExtratropicsNorth AmericaEurope ROC score: 0.66 0.57ROC score: 0.71 0.61 Monthly Forecast Persistence of the probabilities of day 5-11

41. User meeting 14-16 June 200641 Tropical Storms: Monthly Forecast Probability of a tropical storm within 1 degree Day 10-32 Forecast starting on 4 August 2005 Model climatology starting on 4 July 1993- 2004

42. User meeting 14-16 June 200642 Monthly mean precipitation averaged over (60-50N, 10W-2E) 12-36 hours precip forecast Monthly forecast day 5-11

43. User meeting 14-16 June 200643 Monthly mean precipitation averaged over (60-50N, 10W-2E) 12-36 hours precip forecast Monthly forecast day 12-18

44. User meeting 14-16 June 200644 ECMWF Forecast of SSTs issued in May

45. User meeting 14-16 June 200645 Blue is good, yellow is bad But based on 15 years, sampling error is substantial for local values, so spatial distribution is unreliable except where skill is high

46. User meeting 14-16 June 200646 System 3 experimentati on: 10m zonal wind bias Too weak easterlies Oper. system MJJ (1987-2003) m 2-4 Cy 29r1 Cy 29r3

47. User meeting 14-16 June 200647 MJO real-time forecast

48. User meeting 14-16 June 200648 Tropical storm seasonal forecast for 2006 ECMWF Forecast issued in May

49. User meeting 14-16 June 200649 observed SST anomalies DJF 2006 Ecmwf SST predictions for DJF 2006 Eurosip SST predictions