Federal Department of Home Affairs FDHAFederal Office of Meteorology and Climatology MeteoSwiss

WG 4 activities

Federal Department of Home Affairs FDHAFederal 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 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

Present systemx = 10 kmz = 40 MLt = 90 sngp = 306x258x40 =

3.157.920fcst range = 132hcost = 640 BU x runelapsed time = 45 min

COSMO-LEPS at 7 km (cleps_7): the answer to forecasters’ dream?

New systemx = 7 kmz = 40 MLt = 72 sngp = 510x405x40 =

8.262.000fcst range = 132hcost = 1925 BU x runelapsed 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 kmCOSMO-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 2008Pierre.Eckert[at]meteoswiss.ch

2. Postprocessing

Provide standard interface for internal postprocessingWG6

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 2008Pierre.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 2008Pierre.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 2008Pierre.Eckert[at]meteoswiss.ch

The problem

1960 1970 1980 1990 2000 2010

Quality of models

Expectations from models

11 COSMO General meeting ¦ Cracow, September 2008Pierre.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 forecastersPromises: from modellers

12 COSMO General meeting ¦ Cracow, September 2008Pierre.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 2008Pierre.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.