1. THE NEW FRENCH OPERATIONAL CONVENTIONAL RADAR PRODUCTS Pierre Tabary Centre de Météorologie Radar, Direction des Systèmes d’Observation, Météo France pierre.tabary@meteo.fr

2. The French operational radar network  In 2006 : 24 radars of different wavelength (8 S-band, 16 C-band) and type (GEMATRONIK, THOMSON, …)  All radars are equipped with the same « home-made » radar processor (CASTOR2, See the contribution of Parent-du-Châtelet et al. to the 2001 Radar Conference)  Doppler processing (« staggered-PRT », See Tabary et al., 2005, JAOT) and products are gradually introduced  all radars will be Doppler by 2008;  Polarimetry is currently tested on the Trappes (Paris) radar (See Poster 4.13 by Gourley et al.)  8 polarimetric radars by the end of 2006 ?

3. Current operational products Rainfall intensity maps (  Surveillance, Nowcasting, Aviation safety, …) Single radar (Bollène)Composite (France)  1 km² x 5 minutes;  Constant pseudo-CAPPI composition;  Dynamical ground-clutter suppression;  No VPR nor partial beam- blocking correction;  Marshall-Palmer Z-R relationship; 9 September 2002 09.00 UTC Radar QPE (  Hydrology)  Single radar only;  Available every 15 minutes;  No radar – rain gauge real-time adjustment; 24h accumulation – Toulouse radar – Start = 16 April 2005 06.00 UTC

4. The new conventional radar products Radar QPE  Hydrology  Pixel-by-pixel composition (Joss and Lee 1995);  VPR correction (Kitchen et al. 1994, Andrieu et al. 1995)  Partial beam blocking correction (orogenic : Delrieu et al. 1995 and non-orogenic : use of long-term accumulations);  Enhanced frequency : 5 minutes (  Urban applications);  Systematic generation of quantitative quality indexes; Single radar Composite Radar « Detection product »  Nowcasting  Maximum reflectivity along the vertical;  Bright-band correction only;  Partial beam blocking correction ;  Systematic generation of detailled quality indexes; Single radar Composite

5. ? RR3 Unshielded, not in the bright-band, but high RR2 unshielded, not too high, but in the bright band RR1 low but shielded 1 2 3 Courtesy of JJ Gourley (NSSL) RR1RR2RR3 RR1 corr  1 RR2 corr  2 RR3 corr  3 Correction for VPR, partial beam-blocking, ground-clutter and advection RR best =  i  i RR i corr /  i  i  best =MAX i (  i ) Weighted linear combination The new radar QPE Try to get the best surface estimation from the i th tilt Assign a weight to each estimation

6. The VPR correction Kitchen et al. 1994; Kitchen 1996; Andrieu et al. 1995, Fabry and Zawadzki 1995 Simulate – for each VPR candidate - the expected radar observations (ratio curves) Simulate VPR candidates The four parameters can only take a limited number of predetermined, climatology-based values Observed radar measurements (ratio curves) Optimal VPR Correction / extrapolation down to ground-level A conceptual four-parameter VPR 3dB beamwidth A guess is provided by the model

7. Comparison of radar-derived Freezing Level Heights with radiosonde 0°C (dry and wet bulb) heights

8. Illustration of Single-radar QPE 24 h accumulation – 20050206 - Opoul radar Old QPE (HYDRAM)New QPE (PANTHERE)Quality indexes 0 (purple) = excellent 255 (red)= bad Proposed (empirical) formula for the quality index:  = exp[-(h-h terrain ) / h 0 ] x (1-T/100) 1/1.6 0 if ground-clutter or strongly shielded (T > 70%) with : h = altitude of the beam, h0 = 1 km and T = occultation rate (%)

9. Are the proposed quality indexes relevant ? Is there a correlation between radar vs. rain gauge scores and the quality indexes ? 15 episodes included. Each curve corresponds to one episode. The dotted curve is the mean Nash criterion Corr. coefficient 0 (good) Quality indexes 200 (bad)

10. Illustration of composite QPE 24 h accumulation – 20050206 – 7 radars of Southern France Composite QPE Composite quality index map R composite =   jradar R jradar /   jradar  composite = MAX jradar (  jradar ) Applications  NWP QPF verification;  Radar – rain gauge adjustment;  Assimilation in hydrologic models;

11. The Single-radar and composite « detection product » Attenuation by rainPartial beam blocking Altitude Status of the pixelBright band correction 3-level quality index Advection duration Maximum reflectivity

12. The Single-radar and composite « detection product » Attenuation by rainPartial beam blocking Altitude Status of the pixelBright band correction 3-level quality index Advection duration Maximum reflectivity

13. The Single-radar and composite « detection product » Attenuation by rainPartial beam blocking Altitude Status of the pixelBright band correction 3-level quality index Advection duration Maximum reflectivity

14. The Single-radar and composite « detection product » Attenuation by rainPartial beam blocking Altitude Status of the pixelBright band correction 3-level quality index Advection duration Maximum reflectivity

15. The Single-radar and composite « detection product » Attenuation by rainPartial beam blocking Altitude Status of the pixelBright band correction 3-level quality index Advection duration Maximum reflectivity

16. The Single-radar and composite « detection product » Attenuation by rainPartial beam blocking Altitude Status of the pixelBright band correction 3-level quality index Advection duration Maximum reflectivity

17. The Single-radar and composite « detection product » Attenuation by rainPartial beam blocking Altitude Status of the pixelBright band correction 3-level quality index Advection duration Maximum reflectivity

18. The Single-radar and composite « detection product » Attenuation by rainPartial beam blocking Altitude Status of the pixelBright band correction 3-level quality index Advection duration Maximum reflectivity

19. The Single-radar and composite « detection product » Attenuation by rainPartial beam blocking Altitude Status of the pixelBright band correction 3-level quality index Advection duration Maximum reflectivity

20. The Single-radar and composite « detection product » Attenuation by rainPartial beam blocking Altitude Status of the pixelBright band correction 3-level quality index Advection duration Maximum reflectivity

21. The Single-radar and composite « detection product » Attenuation by rainPartial beam blocking Altitude Status of the pixelBright band correction 3-level quality index Advection duration Maximum reflectivity

22. The Single-radar and composite « detection product » Attenuation by rainPartial beam blocking Altitude Status of the pixelBright band correction 3-level quality index Advection duration Maximum reflectivity

23. The Single-radar and composite « detection product » Attenuation by rainPartial beam blocking Altitude Status of the pixelBright band correction 3-level quality index Advection duration Maximum reflectivity

24. Thank you