Overview

The objective will be to continue to develop a one-stop shop for accessing a multi-model forecasting system. The TIGGE (THORPEX Interactive Grand Global Ensemble) archive continues to be an invaluable resource for research in ensemble forecasting. Although the THORPEX programme concluded at the end of 2014, data providers agreed to continue to contribute to TIGGE and ECMWF agreed to continue as Data Provider and Archive Centre.

TIGGE data is expected to make a major contribution to the WMO THORPEX legacy projects on Polar Prediction (PPP) and High Impact Weather Project (HIWeather). The TIGGE archive started collecting data in 2006, hence holding ten years of multi-model ensemble data comprising 1.5 petabytes, from ten global models, totaling more than 5.4 billion fields at the disposal of the community.

Following the success of TIGGE, a project was established in 2013 by the World Meteorological Organization (WMO) to look into the sub-seasonal to seasonal prediction (S2S). The objectives of S2S are:

• To improve forecast skill and understanding on the sub-seasonal to seasonal timescale with special emphasis on high-impact weather events;
• To promote the Initiative’s uptake by operational centres and exploitation by the applications community;
• To capitalize on the expertise of the weather and climate research communities to address issues of importance to the Global Framework for Climate Services.

The project pays specific attention to the risk of extreme weather, including tropical cyclones, droughts, floods, heat waves and the waxing and waning of monsoon precipitation.

To achieve many of these goals, an extensive archive of sub-seasonal (up to 60 days) forecasts and reforecasts (sometimes known as hindcasts) has been established, following the steps of the TIGGE database for medium-range forecasts (up to 15 days) and the Climate-System Historical Forecast project (CHFP) for seasonal forecasts.

The S2S database is hosted at ECMWF, with a secondary archive at CMA. The data portal was launched in May 2015. At present (June 2016) it contains 40 Terabytes for 1 billion fields of forecast and re-forecasts from 10 data providers. There are 11 data providers planned to contribute to the S2S database.

Activities for the period

• The TIGGE archive will continue to grow routinely with output from the data providers. This will involve all the modifications necessary to accommodate the implementations of new versions of the data providers’ models;
• The TIGGE archive be extended to store output from ocean waves components through model improvements (coupled atmosphere-wave systems);
• The S2S database will be extended to include stratospheric levels and oceanic variables. The archiving of oceanic data is partly motivated by the fact that upper-ocean variability is an important source of predictability at the extended range. The inclusion of ocean output is planned for the end of 2016, with the uptake by users and applications in 2017.

Future Plans

• TIGGE would naturally feed into the development of a Global Interactive Forecast System (GIFS) to coordinate advance warnings and forecasts of high impact weather events to mitigate loss of life and property, to be developed through voluntary contributions of national, regional, and international organizations.
• The S2S archive will foster the research on the production and further use of re-forecast data. An extensive re-forecast set spanning several years is needed to calculate model bias, which in some cases can also be used to evaluate skill.

Resources

All activities and resources necessary to support the creation of TIGGE and S2S database and the data portals to provide users with access to such data are part of ECMWF’s contributions to WMO Research Programmes, such as World Climate Research Programme (WCRP) and the World Weather Research Programme (WWRP).

Leadership

• Manuel Fuentes (ECMWF)  Manuel.Fuentes@ecmwf.int
• Chinese Meteorological Administration (CMA)/China.

Contributors

Members: Australia, Austria, Brazil, Canada, Denmark, France, Germany, Hungary, Italy, Japan, Russian Federation, South Korea, United Kingdom, United States.

Participating Organizations: WMO.

Leadership & Contributors (this list is being populated)

Role	Name	Member/PO	Implementing Entity	Email
Lead	Manuel Fuentes	ECMWF	ECMWF	manuel.fuentes@ecmwf.int