Use of the Hirlam NWP Model at Met Éireann (Irish Meteorological Service) (James Hamilton -- Met Éireann)

COMPUTER SYSTEM and VERSIONS of HIRLAM IBM RS/6000 SP : 9-nodes each with 4-CPU’s Operational Hirlam : 438x284 grid pts; 31-levels Nested Hirlam : 222x210 grid pts; 40-levels LINUX PC : Twin Xeon Processors [2.0Ghz] Backup Hirlam : 218x144; 31-levels LINUX PC : Twin Xeon Processors [500Mhz] Hourly Hirlam : 97x98 grid pts; 24-levels

OPERATIONAL HIRLAM … IBM RS/6000 SP HIRLAM 5.0.1 with 3DVAR 3-Hour assimilation cycle with 48-hour forecasts every 6-hours Rotated lat/long 0.15x0.15 grid with 438x284 grid points Hybrid [eta] coordinates with 31-levels CBR vertical diffusion scheme; Sundqvist condensation scheme STRACO cloud scheme; Savijarvi radiation scheme Digital filter initialisation Two time-level Semi-Lagrangian semi-implicit scheme Use of ‘frame’ boundaries from ECMWF

BACKUP HIRLAM … LINUX-PC [Dual 2.0Ghz CPU] HIRLAM 4.3.5 with OI-Analysis 3-Hour assimilation cycle with 48-hour forecasts every 6-hours Rotated lat/long 0.30x0.30 grid with 218x144 grid points Hybrid [eta] coordinates with 31-levels SAME AREA AS OPERATIONAL HIRLAM

NESTED HIRLAM … IBM RS/6000 SP HIRLAM 6.0.0 with 3DVAR 3-Hour assimilation cycle with 24-hour forecasts every 6-hours Model runs at intermediate hours … 03Z, 09Z, 15Z, 21Z Rotated lat/long 0.12x0.12 grid with 222x210 grid points Hybrid [eta] coordinates with 40-levels Kain-Fritsch/Rasch-Kristjansson convection/condensation scheme ISBA surface scheme Output post-processed with MOS

HOURLY HIRLAM ... LINUX-PC [Dual 500Mhz CPU] HIRLAM 4.3 with OI Analysis Hourly assimilation cycle with hourly analysis and 3-hour forecast Rotated lat/long 0.15x0.15 grid with 97x98 grid points Hybrid [eta] coordinates with 24-levels Analysis shown on public web-site

OPERATIONAL USES of HIRLAM General Forecasting Forecast guidance out to 48-hours WAM wave model Forecast 10-metre winds used to drive model Roadice Prediction System Forecast parameters are used as first guess for [human] forecaster SATREP Overlay on satellite plots [ZAMG SATREP analysis scheme]

RESEARCH ACTIVITIES Better Specification of B.C.’s for NWP models Operational Implementation of Nested System Regional Climate Analysis Modelling & Prediction Centre Community Climate Change Consortium for Ireland [RCAMPC and C4I]

Purchase small experimental Linux-Cluster FUTURE PLANS … Purchase small experimental Linux-Cluster Budget of approx Euro 50k Use as backup for main computer [Operational Hirlam] Gain experience with Linux clusters Investigate MOS/Neural-Nets for Post-Processing Use Hirlam as input to Point Data-Base

Thank You