Federal Department of Home Affairs FDHA Federal Office of Meteorology and Climatology MeteoSwiss WG 4 activities

Federal Department of Home Affairs FDHA Federal Office of Meteorology and Climatology MeteoSwiss 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  “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

Present system  x = 10 km  z = 40 ML  t = 90 s ngp = 306x258x40 = fcst range = 132h cost = 640 BU x run elapsed time = 45 min COSMO-LEPS at 7 km (cleps_7): the answer to forecasters’ dream? New system  x = 7 km  z = 40 ML  t = 72 s ngp = 510x405x40 = fcst range = 132h 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  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).

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 GRIB2 format; Future plans (2008 and 2009) 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

7 COSMO General meeting ¦ Cracow, September 2008 Pierre.Eckert[at]meteoswiss.ch 2. Postprocessing Provide standard interface for internal postprocessing  WG6 WG4: 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 …

8 COSMO General meeting ¦ Cracow, September 2008 Pierre.Eckert[at]meteoswiss.ch 3. Use and interpretation of models COSMO-2 RADAR mm/24h Forecasters: we all started to use WRF for precipitation!

9 COSMO General meeting ¦ Cracow, September 2008 Pierre.Eckert[at]meteoswiss.ch 3. Use and interpretation of NWP models Serious problems with “non-equilibrium convection cases ». Neither the 7km (parametrised convection) nor the 2km (explicit deep convection) predict precipitation correctly (even yes or no). Who to blame? The bad model(s)? The forecasters overconfident in model(s)?

10 COSMO General meeting ¦ Cracow, September 2008 Pierre.Eckert[at]meteoswiss.ch The problem Quality of models Expectations from models

11 COSMO General meeting ¦ Cracow, September 2008 Pierre.Eckert[at]meteoswiss.ch Expectations / promises Small grid spacing  high resolution forecast Good (perfect) timing Desire for sophisticated parameters: Surface temperature Rainfall Cloudiness Fog Wind gusts ….. Expectations:from forecasters Promises: from modellers

12 COSMO General meeting ¦ Cracow, September 2008 Pierre.Eckert[at]meteoswiss.ch 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?

13 COSMO General meeting ¦ Cracow, September 2008 Pierre.Eckert[at]meteoswiss.ch WG4: 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.