ECMWF medium range forecasts and products

1. ECMWF medium range forecasts and products Model changes (Medium Range) Forecast performance New products/ Future developments F. Lalaurette, ECMWF, Met’Ops

2. Changes to the medium range forecasting system • 29 June 2004:Cy28r2 (early delivery suite) • By shifting the 12h 4Dvar data assimilation window by 6h, and running an early additional, uncycled 6h 4Dvar, operational products are disseminated around 4h earlier without any noticeable impact on the forecast quality. • 29 September 2004: Cycle 28r3 • Revised convection scheme numerics and calling of the cloud scheme , use of tangent linear and adjoint of vertical diffusion in the 1st minimization of 4D-Var , Reduction of radiation frequency to 1 hour in the high-resolution forecasts , Improved numerics of surface tile coupling • New Radiative Tranfer code (RTTOV-8) , minor revisions to ATOVS and AIRS usage , assimilation of MSG clear-sky radiances, of GOES 9 BUFR AMVs and of SCIAMACHY ozone products from KNMI , Correct error in AMSU-B usage over land , Activate EARS data • Blacklist SYNOP humidity data at local night time , Increased use of radiosonde humidity: use RS90 to -80C, RS80 to -60C, other sensors to -40 C. Proper cycling of the assimilation of the wave altimeter and land surface data (FG moved from 00 and 12 UTC to 06 and 18 UTC) • EPS Gaussian sampling for extra-tropical singular vectors, instead of selection and rotation, revision of tropical cyclones (TC) perturbations (extension from 25 S 25 N to 40 S 40 N, orthogonalisation with respect to extra-tropical singular vectors, optimisation regions based on predicted TC tracks from previous EPS run)

3. Changes to the medium range forecasting system • 7 October 2004 • Monthly forecasts are run operationally on a weekly basis (Thursdays). • 9 November 2004: • All four BC-project analyses use background fields generated from the latest operational 4D-var analysis • 16 March 2005: • Tropical Cyclone tracks from the Deterministic and EPS forecasts are disseminated on the GTS in BUFR format;

4. Changes to the medium range forecasting system • 5 April 2005: Cy29r1 • New moist boundary layer scheme (more stratocumulus clouds in subtropical highs and more low level clouds in some extratropical winter conditions); • Wavelet formulation introduced in the representation of background error statistics (Jb), the tuning of which has been based on Data Assimilation ensemble runs; • Revised use of surface pressure observations: METAR are activated; all surface pressure data are subject to an adaptative bias correction; observation error are reduced; PAOB observations are not used any more; • MODIS winds from AQUA are activated (only TERRA before); AQUA winds observation error is reduced; 10 AIRS channels are blacklisted (pb strato. Humidity); • Bugfix in the first time step of the semi-Lagrangian treatment of the physics was fixed; snow cover tile coupling has been revised; a new dissipation source function has been introduced for the oceanic wave modelisation; • several technical implementation for the assimilation of rain, of GPS data and for the variational bias correction of satellite radiances introduced but not activated • Nonlinear Normal Mode Initialisation for the EPS has been discontinued.

5. ECMWF medium range forecasts and products Model changes (Medium Range) Forecast performance Long term evolution Winter performance Tropical Cyclones and Heavy Rain New products/ Future developments F. Lalaurette, ECMWF, Met’Ops

6. EPS spread/ Error

7. EPS spread/ Error

8. Time series (N.Extratropics)

9. Time series (Europe)

10. Winter 2005 vs 1998-2004 (Europe, Z500, ANC)

11. Winter 2005 vs 1998-2004 (ET NH, Z500, ANC)

12. Winter 2005 vs previous wintersT511 vs EPS Mean (Europe, T850, Day 7)

13. Gains - ECMWF(Z500 cumulated skill – ref. is average from other centres)

14. Gains - Exeter (Z500 cumulated skill – ref. is average from other centres)

15. Gains - NCEP(Z500 cumulated skill – ref. is average from other centres)

16. Gains - DWD (Z500 cumulated skill – ref. is average from other centres)

17. Predictability variations (courtesy M. Köhler and A. Ghelli)

18. Waves vs other centres (Courtesy J. Bidlot)

19. New web pages (TCs)

20. 2003-2004 TC history

21. TC Verification 2004 (Atlantic ocean)

22. TC Verification (2004, all basins)

23. TC Verification (2003, all basins) • 2004 vs 2003: • Reduced gap T255 vs T511 • Except for pressure?

24. TC Probabilities verification

25. Extreme Forecast Index Verification (1% extreme events defined with respect to EUMETNET/ECSN Climate Atlas of Europe data)

26. Probability >20mm verification(1% extreme events defined with respect to EUMETNET/ECSN Climate Atlas of Europe data)

27. Verification summary • Outstanding performance from previous years is confirmed • Some problems with low level clouds • First steps in verifying Severe Weather forecasts • Tropical Cyclone forecasts have improved significantly last year • Still core pressure is underestimated • Slow biais • Some over-confidence in Strike Probability Maps; useful guidance • First steps towards EFI verification have been taken

28. ECMWF medium range forecasts and products Model changes (Medium Range) Forecast performance New products/ Future developments F. Lalaurette, ECMWF, Met’Ops

29. Seamless system • The planned merge at increased resolution of the EPS and Monthly forecast system in 2005/06 will mean some re-thinking () of the product generation • Unified EPSgrams • More “weather-related” monthly forecast maps • “Monthly-forecast-like” hindcasts for the medium-range

30. 2003-2004 TC history

31. Extended EPSgram (courtesy Mark Rodwell)

32. Extended EPSgram (courtesy Mark Rodwell)

33. Day 12-18 Day 5-11 New Monthly forecast maps (courtesy F. Grazzini)

34. New Medium range Hindcasts (“à la Monthly”) • Running an additional EPS control suite in dynamical adaptation mode (48h forecast) • Initial conditions from ERA40 (1971-2000) • Use latest resolution/ physics • Same post-processing as for EPS (surface + a few pressure and PV levels) • Cost is only like adding six 10-days Control runs per day • Will allow a quick adaptation of the EFI to the increased EPS resolution in autumn, and an extension of the EFI (and other calibrated probabilistic products) to other parameters than rain, T2m and wind

35. New EPS Control climate (Reading, 15/1) (courtesy E. Zsóter) EPS Forecast Current EPS climate 30-years 48h hindcasts (+/-15 days)

36. Global EFI maps

37. 70°W 60°W 50°W 40°W 30°W 20°W 10°W 50°N 50°N 40°N 40°N 30°N 30°N 20°N 20°N 10°N 10°N 0° 0° 70°W 60°W 50°W 40°W 30°W 20°W 10°W Tropical Cyclogenesis: 1) Karl OBSERVATION TRACKING FOR KARL (12L) CYCLONE LIFETIME : 20040916 TO 20040924 4 (TYP/HUR) 1 (TD) 2 (TS) 3 (STS)

38. Tropical Cyclogenesis: 1) Karl 1st strike probability map (17/9)

39. 1016 1016 1016 L H Tropical Cyclogenesis: 2) Karl D5 forecast Valid 1709 12UTC 20040912 12UTC ECMWF FC t+120 VT: 20040917 12UTC Surf:msl/10v (Exp: 0001 ) SEVERE TROPICAL STORM KARL ( 12L ) Estimated Core Pressure 994 hPa OBSERVATION POSITION and STRENGTH 1 (TD) 2 (TS) 3 (STS) 4 (TYP/HUR) 40°W 20°N 20°N 10°N 10°N 40°W

40. Observation (24/9) Tropical Cyclogenesis: 3) Karl “Feature tracking” (no seed, Hodges, 1994)

41. FRANCES (25/8-7/9)

42. Frances: 1st strike probability map (26/9)

43. Frances verification (D4 forecast)

44. FRANCES Feature tracking

45. And more… • Data monitoring • New verification package

46. f.lalaurette@ecmwf.int

47. francois.lalaurette@meteo.fr (from 1.9.2005)