1 / 42

Short Range Ensemble Prediction System Verification over Greece Petroula Louka, Flora Gofa

Short Range Ensemble Prediction System Verification over Greece Petroula Louka, Flora Gofa Hellenic National Meteorological Service. HNMS involvement in COSMO-SREPS Task 6. Verification of LM-COSMO ensemble forecasts for Autumn 2006 21 cases of 72-hour forecast horizon, 16 members

tass
Download Presentation

Short Range Ensemble Prediction System Verification over Greece Petroula Louka, Flora Gofa

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. Short Range Ensemble Prediction System Verification over Greece Petroula Louka, Flora Gofa Hellenic National Meteorological Service

  2. HNMS involvement in COSMO-SREPS Task 6 • Verification of LM-COSMO ensemble forecasts for Autumn 2006 • 21 cases of 72-hour forecast horizon, 16 members • Verification domain: Greece • Data used: SYNOP data covering Greece • Parameters verified: • 2m temperature • Mean Sea Level Pressure (MSLP) • Precipitation • Statistical analysis of the results COSMO 9th General Meeting

  3. COSMO-SREPS domain COSMO 9th General Meeting

  4. Greek SYNOP stations 30 stations covering Greece COSMO 9th General Meeting

  5. Statistical analysis methods • For continuous parameters such as Temperature and MSLP • Bias • RMSE • For non-continuous parameters (precipitation) • Deterministic approach • Multi-category contingency tables (limits: 0-0.1, 0.1-4.0, 4.0-9.0, >9.0 mm) • POD, FAR, ETS, etc • Probabilistic approach (e.g., ROC diagrams) (average of all 16 members) COSMO 9th General Meeting

  6. (1,1) (1,2) (1,3) (2,1) (2,2) (2,3) (3,1) (3,2) (3,3) Point selection Interpolated value Closest point COSMO 9th General Meeting

  7. COSMO-SREPS members COSMO 9th General Meeting

  8. Temperature & MSLP Statistical analysis • Bias and RMSE averaged over all forecast members and stations COSMO 9th General Meeting

  9. 2m Temperature – Bias COSMO 9th General Meeting

  10. 2m Temperature – RMSE COSMO 9th General Meeting

  11. 2m Temperature – Bias COSMO 9th General Meeting

  12. 2m Temperature – RMSE COSMO 9th General Meeting

  13. Mean 2m Temperature SYNOP COSMO 9th General Meeting

  14. MSLP – Bias COSMO 9th General Meeting

  15. MSLP – RMSE COSMO 9th General Meeting

  16. MSLP – Bias COSMO 9th General Meeting

  17. MSLP – RMSE COSMO 9th General Meeting

  18. COSMO-SREPS members COSMO 9th General Meeting

  19. PrecipitationStatistical analysis • Contingency table • Probability Of Detection (POD) to examine the occurrence of the event • False Alarm Ratio (FAR) • Threat Score (TS) to examine the performance of rare events Limits used: 0-0.1 mm, 0.1-4.0 mm, 4.0-9.0 mm, >9.0 mm COSMO 9th General Meeting

  20. PrecipitationContingency table 4x4 tablefor each 6-hour forecast COSMO 9th General Meeting

  21. Precipitation – Exampleof contingency table COSMO 9th General Meeting

  22. IFS GME NCEP UKMO Precipitation – POD0-0.1 mm COSMO 9th General Meeting

  23. IFS GME NCEP UKMO Precipitation – POD0.1-4.0 mm COSMO 9th General Meeting

  24. IFS GME NCEP UKMO Precipitation – FAR0-0.1mm COSMO 9th General Meeting

  25. IFS GME NCEP UKMO Precipitation – FAR0.1-4.0 mm COSMO 9th General Meeting

  26. Tiedtke, pat_len500 Kain-Fritsch, pat_len500 Tiedtke, tur_len1000, pat_len500 Tiedtke, pat_len10000 Precipitation – POD COSMO 9th General Meeting

  27. Tiedtke, pat_len500 Kain-Fritsch, pat_len500 Tiedtke, tur_len1000, pat_len500 Tiedtke, pat_len10000 Precipitation – FAR COSMO 9th General Meeting

  28. Example of Precipitation field 28.0mm 03/11/06 LM3 Period 00-06 LM3: IFS, tiedtke (T), tur_len (1000), pat_len (500) 21.0mm COSMO 9th General Meeting

  29. Example of Precipitation field 28.0mm 03/11/06 LM7 Period 00-06 LM7: GME, tiedtke (T), tur_len (1000), pat_len (500) 21.0mm COSMO 9th General Meeting

  30. Example of Precipitation field 28.0mm 03/11/06 LM11 Period 00-06 LM11: NCEP, tiedtke (T), tur_len (1000), pat_len (500) 21.0mm COSMO 9th General Meeting

  31. Example of Precipitation field 28.0mm 03/11/06 LM15 Period 00-06 LM15: UKMO, tiedtke (T), tur_len (1000), pat_len (500) 21.0mm COSMO 9th General Meeting

  32. Lightnings observed COSMO 9th General Meeting

  33. Satellite image03/11/2006 Geostationary 00UTC COSMO 9th General Meeting

  34. Example of Precipitation field 03/11/06 LM3 Period 36-42 LM3: IFS, tiedtke (T), tur_len (1000), pat_len (500) COSMO 9th General Meeting

  35. Example of Precipitation field 03/11/06 LM7 Period 36-42 LM7: GME, tiedtke (T), tur_len (1000), pat_len (500) 0.0mm >5mm COSMO 9th General Meeting

  36. Example of Precipitation field 03/11/06 LM11 Period 36-42 LM11: NCEP, tiedtke (T), tur_len (1000), pat_len (500) COSMO 9th General Meeting

  37. Example of Precipitation field 03/11/06 LM15 Period 36-42 LM15: UKMO, tiedtke (T), tur_len (1000), pat_len (500) >5mm 0.5mm COSMO 9th General Meeting

  38. Lightnings observed COSMO 9th General Meeting

  39. Satellite image04/11/2006 Geostationary 12UTC COSMO 9th General Meeting

  40. Summary – Suggestions • In general, averaged BIAS and RMSE values showed • a small overestimation for MSLP • and statistically acceptable values (~ 2C for 2m Temperature and <5 mb for MSLP) apart from a few specific forecasts for which RMSE is large compared to the mean value. COSMO 9th General Meeting

  41. Summary – Suggestions • The sample used is statistically small for extracting conclusive information regarding the precipitation forecast • The available results showed that • Precipitation amounts are generally overestimated • The influence of the different initial conditions on the forecasted precipitation field is evident • The influence of convective scheme and turbulent length scale is important mainly on forecasting accurately the presence of a precipitation event (POD value) COSMO 9th General Meeting

  42. Future plans • Application of the existed statistical methods to a larger sample • Extend the statistics to include other meteorological parameters • Investigation of precipitation ensemble forecasts using probabilistic approach (ROC diagrams, etc) • Possibility of examining the performance of ensemble forecasting on upper air meteorology COSMO 9th General Meeting

More Related