User guide to ECMWF forecast products

User guide product montage

14 May 2018

A new edition of ECMWF’s user guide is now available online. The ECMWF Forecast User Guide helps forecasters and other meteorologists to make the best use of the forecast products from ECMWF.

The user guide provides all the tools needed for correct interpretation of ECMWF products, enabling users to deliver a high-quality service to their own customers. It also encourages users to employ new or previously overlooked forecast techniques.

The guide focuses on the medium range but also covers the increasingly important monthly and seasonal output. The correct use of probabilistic information and of departures from worldwide model climatologies is stressed throughout.

While the emphasis is on ECMWF’s own web-based products, including ecCharts output, the content is also relevant to users who reference gridded data imported onto their own dedicated forecaster workstations.

The Integrated Forecasting System (IFS) is the numerical model engine that delivers ECMWF products. It is constantly improving and evolving. The guide explains how the IFS works, what recent changes there have been and what these mean for forecast quality, complementing the more detailed scientific documentation on new model cycles that ECMWF also provides.

The guide details how physical processes are represented in the IFS, and the limitations of these representations. It also describes the ways in which observation usage is optimised. In parallel with IFS changes, many new products have been added in recent years, and these are comprehensively discussed too, with strengths and weaknesses highlighted in each case.

Up to now, the user guide has been available to download from ECMWF’s website as a PDF document. Now in web-based format, this new edition will be updated swiftly as the IFS, the products and our understanding evolve. In future, we are aiming for the web platform to allow comments and discussions.

The user guide also complements existing forecaster-oriented resources such as the Severe Event Catalogue and Known IFS forecasting issues.

ECMWF Forecast User Guide