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Federal Department of Home Affairs FDHA Federal Office of Meteorology and Climatology Meteo. Swiss WG 4 activities
Federal Department of Home Affairs FDHA Federal Office of Meteorology and Climatology Meteo. Swiss 1. COSMO LEPS
Feasibility study of COSMOLEPS at 7 km (cleps_7) Motivations: Provide a more detailed description of mesoscale processes by incresing the horizontal resolution. Do not lose a “reasonable advantage” against ECMWF EPS, which will go to x=25 km during 2009. “Keep the pace” with deterministic model ( x~ 2 -3 km): if the gap in resolutions between deterministic and probabilistic systems is too large, the two systems go for different solutions (that is, they forecast different weather!). from 10 to 7 km (plus small domain extensions) does not seem a lot
COSMO-LEPS at 7 km (cleps_7): the answer to forecasters’ dream? Present system x = 10 km z = 40 ML t = 90 s ngp = 306 x 258 x 40 = 3. 157. 920 fcst range = 132 h cost = 640 BU x run elapsed time = 45 min New system x = 7 km z = 40 ML t = 72 s ngp = 510 x 405 x 40 = 8. 262. 000 fcst range = 132 h cost = 1925 BU x run elapsed time = 138 min … cleps_7 is about 3 times more expensive than the present configuration new computer at ECMWF being installed Computer resources for each ECMWF member state will increase by a factor of 5 (five) and ….
The dream is possible COSMO-LEPS 10 km COSMO-LEPS 7 km Ø the grid of cleps_7 would be almost identical to that of COSMO-EU, this making easier and cleaner the use of initial fields provided by DWD (e. g. soil moisture analysis).
Future plans (2008 and 2009) • test the use of the Soil Moisture Analysis fields provided by DWD; • run cleps_7 for ~ 40 days in autumn 2008 and assess the impact; • within TIGGE-LAM, develop coding of COSMO-LEPS output files in GRIB 2 format; • migration to the new machine at ECMWF; • use a better snow analysis (possibly provided by DWD or Meteoswiss); • extend the cluster analysis so as to consider not only ECMWF EPS, but also UKMO MOGREPS as global ensemble providing ic’s and bc’s (first tests); • implement cosmoleps_7; • gaining from COSMO-SREPS experience, introduce more model perturbations; • test COSMO-LEPS nested on the under-development ECMWF EDA over MAP D‑PHASE period; • optimise use of reforecasts + calibration of wind gust; • support CONSENS + verification
2. Postprocessing Provide standard interface for internal postprocessing WG 6 WG 4: Provide standard internal postprocessing methods (i. e. formula catalog) • Instability indices • Front parameter • Synthetic satellite images • … Exchange external postprocessing methods • KF, MOS on wind, wind gusts • … COSMO General meeting ¦ Cracow, September 2008 Pierre. Eckert[at]meteoswiss. ch 7
3. Use and interpretation of models Forecasters: we all started to use WRF for precipitation! mm/24 h COSMO-2 COSMO General meeting ¦ Cracow, September 2008 Pierre. Eckert[at]meteoswiss. ch RADAR 8
3. Use and interpretation of NWP models Serious problems with “non-equilibrium convection cases » . Neither the 7 km (parametrised convection) nor the 2 km (explicit deep convection) predict precipitation correctly (even yes or no). Who to blame? • The bad model(s)? • The forecasters overconfident in model(s)? COSMO General meeting ¦ Cracow, September 2008 Pierre. Eckert[at]meteoswiss. ch 9
The problem Quality of models Expectations from models 1960 1970 1980 COSMO General meeting ¦ Cracow, September 2008 Pierre. Eckert[at]meteoswiss. ch 1990 2000 2010 10
Expectations / promises • Small grid spacing high resolution forecast • Good (perfect) timing • Desire for sophisticated parameters: • Surface temperature • Rainfall • Cloudiness • Fog • Wind gusts • …. . Expectations: Promises: from forecasters from modellers COSMO General meeting ¦ Cracow, September 2008 Pierre. Eckert[at]meteoswiss. ch 11
Discussion points • What is really the quality of a model? • Which model is better? • In which situation? • For which parameter? • … • In a convective situation, do we look a the model rainfall pattern or a TS index? Or synoptics? • How does it compare with a statistical postprocessing on a global model? • Conditional verification can (must) be used • How can forecasters specify the conditions (weather classification, stability, season, …) • How can these informations be communicated? COSMO General meeting ¦ Cracow, September 2008 Pierre. Eckert[at]meteoswiss. ch 12
WG 4: Interpretation and applications Discussion on these topic also started (recently) within SRNWP • Catalog and exchange of posprocessing methods • Listing and exchange of end-user applications (agriculture, aviation, …) • Use and interpretation of models? I am open to any collaborative suggestions for activities in this WG. COSMO General meeting ¦ Cracow, September 2008 Pierre. Eckert[at]meteoswiss. ch 13