TIGGE-LAM improves regional ensemble forecasts

The World Weather Research Programme has launched a new tool to improve regional ensemble forecasts of high-impact weather and so strengthen early warning and disaster prevention.

A single web portal hosted by the European Centre for Medium Range Weather Forecasts (ECMWF) called TIGGE-LAM is now available. It currently groups five European ensemble systems in a standard data format, and five more will be added in the near future.

TIGGE-LAM is an extension of the THORPEX Interactive Grand Global Ensemble (TIGGE) archive to include weather forecasts from limited area model (LAM) ensembles. Five European ensemble systems are now available in a standard data format through a single web portal at ECMWF [see table]. These forecasts are produced on grids between 10 and 2 km resolution and provide detailed information for the short range, up to a few days ahead. This complements the larger-scale information provided by the global data in the established TIGGE archive.

In the TIGGE project, ten of the leading global weather forecast centres are providing regular global ensemble predictions to support research, particularly addressing predictability, dynamical processes and the development of probabilistic forecasting methods. TIGGE has become a focal point for a range of research projects, including research on ensemble forecasting, predictability and the development of products to improve the prediction of severe weather.

THe Observation System Research and Predictability EXperiment (THORPEX) is a 10-year international research programme that was established in 2005 to accelerate improvements in the accuracy and utility of high-impact weather forecasts up to two weeks ahead. THORPEX is part of the World Weather Research Programme and is a key research component of WMO’s disaster risk reduction programme.

TIGGE-LAM complements the larger-scale information provided by the global data in the established TIGGE archive. It will enable users to compare models and improve the methodologies for the generation and application of regional ensemble forecasts. It will also provide valuable feedback to global ensemble developments as the resolution of these systems is planned to increase significantly in the coming years. All contributions have been coordinated at ECMWF.

The TIGGE-LAM archive has been developed as part of the EU-funded GEOWOW project to improve Earth observation data discover, accessibility and exploitability. It is part of the weather contribution to the GEO System-of-Systems (GEOSS) and is accessible through the GEO Common Infrastructure (GCI).

TIGGE-LAM was launched at a conference at WMO headquarters on 19 March. Speaking at the event, David Richardson, Head of Evaluation at ECMWF said: “Although originally proposed in 2007, the TIGGE-LAM project only recently came to fruition thanks to GEOWOW. For the first time, we can easily access all of these ensembles and study their performance to improve our understanding. Having data from five European ensemble systems is a great start, and another five providers will join the scheme shortly.”

Notes to editors:

• The TIGGE-LAM data portal is available at http://apps.ecmwf.int/datasets/data/tigge_lam/
• More information about the TIGGE-LAM project is available at http://software.ecmwf.int/wiki/display/TIGGE/TIGGE-LAM and http://www.smr.arpa.emr.it/tiggelam/