The 14^th GA decided a two-stage process to address issues where diversity of approaches are needed : a kick-off brainstorming meeting to be organized by the programme managers of ALADIN, LACE and HIRLAM, CSSI chair and French LTM in May 2010 in Croatia where experts on theoretical aspects from ALADIN/HIRLAM/ECMWF should be invited, in the fields of higher resolution modelling (i.e. all forecast model aspects including the links with data assimilation and EPS but not more on the latter aspects); PAC will then study the conclusions/proposals of this workshop and prepare a scientific vision workshop for 2011 (see Strategic workshop, Bruxelles, 27-29 September 2011).

Thus, the BRainstorming on Advanced Concepts –on High Resolution modelling workshop took place in Supetar, Brac island, Croatia, on 17-20 May 2010.

 Agenda

• Plenary session 1 (chair: Dijana, rapport: Piet)
  • Filip Vana : Dynamics methods for high resolution NWP modeling
  • Piet Termonia: Coupling, nesting and initialization
  • Terry Davies: Nesting and LBC’s, EPS and predictability
• Plenary session 2 (chair: Dijana, rapport: Piet)
  • Jean-Francois Geleyn: Upper air physics
  • Francois Bouyssel: Surface issues for high resolution NWP
  • Sander Tijm: Validation and verification
• Working groups (WG 1-6)
• Plenary session 3 (chair: Jeanette & J-F, rapporteur: Dijana& Piet)
  • Reports WG 1- 6 , Cross-discussion
  • Draft of standpoints (?)

 Preparatory documents

• Planned set-up for the Brac-HR workshop, by the organising committee
• Input to the workshop, by Bent H. Sass, DMI
• Aspects and links between upper-air data assimilation and the Brac discussions, by C. Fischer, Meteo-France
• Major scientific issues for km-scale NWP models, by D. Majewski, DWD for the COSMO Consortium
• Scientific issues for NWP models a (sub)kilometric scale, by C. Wittmann and Y. Wang, ZAMG
• Contribution, F. Vana, CHMI
• Scientific issues for km-scale NWP models, by J. Barkmeijer, KNMI
• An attempt at diagnosing current trends in the physical parametrisation trade for higher resolution modelling, by J-F Geleyn, ALADIN-PM
• Scientific issues to be faced with in the forecast model during the coming years, by L. Bengtsson-Sedlar, SMHI
• Some scientific issues for km scale modeling, by L. Kullman, HMS
• Comments around the surface for the Brac workshop, by L. Rontu, FMI
• Contribution, M. Hortal, INM
• Open views on strategic issues for high-resolution NWP dynamical cores, P. Benard and C. Lac, Meteo-France
• Position paper for the Brac meeting, by L. Gerard and P. Termonia : physics and later boundary conditions
• Scientific issues for new resolution, by CHMI and Bratislava University
• Position paper for the Brac meeting, by J. Vivoda, SHMU : dynamics
• Major scientific issues for km-scale NWP models, by S. Niemala, FMI
• Contribution, by S. Sbii, Maroc-Meteo
• Issues for high resolution modelling of convection, especially from the point of the physics and dynamics, by S. Tijm, KNMI
• Contribution, by E. Kallen, ECMWF
• Contribution, by N. Pristov, EARS
• A proposal for an ‘internal’ and flexible approach to the challenges posed by future high-resolution
  NWP perspectives to the current ALADIN-NH dynamical core, by J-F Geleyn (ALADIN PM) and J. Onvlee (HIRLAM PM)

 Outcome of the Brac Workshop

• the report
  • Areas of broad consensus
  • Areas with divergence of opinions
  • Attempt at a synthesis for future steps
• Appendixes
  • the list of participants
  • Scope of a ‘Kick-off brainstorming meeting about future LAM direct modelling’
  • Some information about the follow-on actions of Brac-HR (compiled by the ALADIN PM)