1. C ontacts: Marit Helene Jensen, Norwegian Meteorological Institute, P.O.Box 43 Blindern, N-0313 OSLO, NORWAY. E-mail: marit.h.jensen@met.no HIRLAM at met.no Met Office Unified Model at met.no A partnership between met.no and Met Office was established in 2002 to develop shared interests in very high resolution NWP capability. The Met Office Unified Model has been implemented for a 3km grid covering southern Norway (280*276*38 grid nodes). Since July 2003 the model has been run daily at 00UTC and 12UTC for 48 hours, with initial field and lateral boundaries from the met.no HIRLAM10 model. Later this autumn quasi-operational runs forced with Met Office Euro-LAM 20km model boundaries will be initiated. Special attention will be given to heavy precipitation events and extreme wind cases. The ability to describe events with heavy snow fall and also melting of snow in spring will be studied carefully. One hour accumulated precipitation as measured from radar observation of the same event. Heavy precipitation event in August 2003 forecasted by UM 3km (+15 hours). UM 3km area with topography. Perturbing HIRLAM with perturbations from ECMWF ensemble system (EPS), targeted to Northern Europe – TEPS The last years the system has been tested using different set-up for the perturbations, with promising results Aim to run the system for longer time periods (at least for several weeks and different seasons) 48h optimization time for targeted singular vectors (TSVs) HIRLAM analyses used The approach presented here: - Perturbed ini. and boundary conditions with ECMWF ensembles based on TSVs + evolved TSVs LAMEPS – Limited Area Model Ensemble Prediction System (with HIRLAM) NWP at met.no Marit Helene Jensen, Dag Bjørge and Inger-Lise Frogner NWP at met.no Marit Helene Jensen, Dag Bjørge and Inger-Lise Frogner HIRLAM version 6.1.0 with 3D-var HIRLAM20 – 0.2 degree resolution, (486*378 grid nodes) - 00, 06, 12 and 18 UTC HIRLAM10 – 0.1 degree resolution, (284*341 grid nodes) - 00 and 12 UTC HIRLAM5 - 0.05 degree resolution, (152*150 grid nodes) – 00 and 12 UTC All with 40 vertical levels HIRLAM is the operational model at met.no. It is run every 6.(12.) hour in three different resolutions: HIRLAM20 and HIRLAM10 are run on ECMWF frames and HIRLAM5 nested within HIRLAM10. HIRLAM20 is run with HIRLAM 3D-VAR assimilation, while HIRLAM10 uses the analyses from HIRLAM20. ECMWF boundaries for HIRLAM10 Test of ECMWF data directly at the boundaries of HIRLAM10 (when two sets of ECMWF frames became available) vs HIRLAM20 outer model boundaries Test period with parallel run: 20021209 - 20030317 Verification area Targeted area SVs Integration area HIRLAM Test period October 2002: 14 days, 18. – 31. January 2003: 14 days, 10. – 24. + 7 days, 25.- 31. May 2003: 19 days (under production) Verification with and without evolved pertubations Without With Verification time: 42h 10 mm/24h Total precipitation Initial perturbations 48 h evolved perturbations LAMEPS (with) EPS OPR EPS Verification time: 66h 2.5 mm/24h Total precipitation LAMEPS (with) EPS OPR EPS Verification time: 66h 30 mm/24h Total precipitation Combination LAMEPS and EPS OPR EPS Verification time: 66h 15 mm/24h Total precipitation Verification time: 66h 30 mm/24h Total precipitation Combination LAMEPS and EPS OPR EPS Black: HIRLAM20 boundaries Red: ECMWF boundaries