Numerical Weather Prediction at DWD COSMOEU Grid spacing

Numerical Weather Prediction at DWD COSMO-EU Grid spacing: 7 km Layers: 40 Global model GME Forecast range: Grid spacing: 40 km 78 h at 00 and 12 UTC Layers: 40 48 h at 06 and 18 UTC Forecast range: 1 grid element: 49 km 2 174 h at 00 and 12 UTC 48 h at 06 and 18 UTC 1 grid element: 1384 km 2 COSMO-DE Grid spacing: 2. 8 km Layers: 50 Forecast range: 21 h at 00, 03, 06, 09, 12, 15, 18, 21 UTC 1 grid element: 8 km 2

Numerical Weather Prediction at DWD COSMO-DE Configuration • Grid spacing: x = 2. 8 km • direct simulation of the coarser parts of deep convection • interactions with fine scale topography • Data assimilation using radar data (LHN) • Time step t = 25 sec • 421 x 461 x 50 grid points ~ 1200 * 1300 * 22 km³ lowest layer in 10 m above ground • 21 -h forecasts from 00, 03, …, 21 UTC • boundary values from COSMO-EU ( x = 7 km) • Operational: 16 April 2007

New DWD Headquarters by June 2008 Offenbach, Frankfurter Strasse 135

New DWD Supercomputer by June 2008 • Invitation to tender out in Q 2, 2007 • Benchmark: Different resolutions of COSMO model • 3 companies bidding • Final decision will be announced by end of October 2007 • Installation phase I in 2008: 2 x 4. 5 TFlop/s sustained • Installation phase II in 2010: Upgrade by at least a factor of 2 • Main cost driver: Ensembles (data assimilation, forecasting)