Proceedings - C-SRNWP Project

Recent Experiences with the INM Multi-model EPS
scheme
García-Moya, J.A., Callado, A., Santos, C., Santos, D., Simarro, J., Orfila, B.
Modelling Area – Spanish Met Service INM
1. Introduction
Forecast of weather risk is the goal for both Medium and Short Range Prediction (Palmer,
2002), being key for this purpose the accurate forecasts of surface weather parameters and
extreme events (convective precipitation, gales…). The probabilistic character of these
forecasts makes convenient trying to see how several Short Range Ensemble Prediction
Systems may help to forecast these events (Hou D. et alt 2001). That was present when in
April 1999 INM included in its NWP plans the aim to prepare a Limited Area Short Range
Ensemble Prediction System. The SAMEX experiment was the reference followed for its
initial development. Along 2001 to 2005 a convenient set of operational well tested limited
area models were imported into INM and implemented in the INM computing System, which
was progressively upgraded until the current CRAY1E. The triggering and consolidation of
the current INM SREPS System have been possible thanks to:
i) the availability of enough computer power;
ii) the stable staff team gathered, which has allowed to overcome the technical difficulties
related to the adaptation of the models to the platform, storage aspects, database
software (MARS like the ECMWF one), post processing, maintenance, monitoring and
verification; and
iii) the following of the recommendations of the workshops and meetings attended.
A description of SREPS at INM with examples of the monitoring procedure and displays of
some products are included in section 2. Description and some results of a verification
exercise both against observations and analyses is covered in section 3. Further work, the
envisaged future of INM SREPS and some conclusions close this presentation.
2. SREPS at INM
The aim of INM SREPS is preparing four times a day, at 00, 06, 12 and 18 UTC, a set of 20
forecast from five limited area models fed each one with boundary conditions from four
global models, and combining the last four ensembles (HH to HH-18) to get a time-lagged
Super-Ensemble of 80 members every six hours.
The five model used are:
Hirlam (http://hirlam.org).
HRM from DWD (German Weather Service).
MM5 (http://box.mmm.ucar.edu/mm5/).
UM from UKMO (United Kingdon Meteorological Office).
LM (Lokal Model) from the COSMO consortium.
and the four global models providing the boundaries are:
ECMWF (European Centre for Medium Range Weather Forecasts)
UM from UKMO (United Kingdon Meteorological Office)
AVN from NCEP (U.S. National Weather Service)
GME from DWD (German Weather Service)
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