17th HEPEX Webinar: 2004-2014 – The rise of the meteorological ensembles in the HEPEX decade

The Webinars are back after a small break over the summer. First out for the season is one of the founding fathers of HEPEX, Roberto Buizza.

Speaker: Roberto Buizza, ECMWF

Date and time: Tuesday, September 30, 2014 3:00 pm GMT Summer Time  (UTC+01:00)

Register: https://ecmwf.webex.com/ecmwf/onstage/g.php?t=a&d=954436834

Preview of the seminar:17th_HEPEX_Webinar_Buizza

Abstract: In 2004, ECMWF hosted the first workshop that discussed the proposal for an International Hydrological Ensemble Prediction Experiment (HEPEX). This is how HEPEX started, with one of its main objectives being to demonstrate how to produce reliable “engineering quality” hydrological ensemble forecasts that can be used to assist the water resources sector to make decisions that have important consequences for the economy and for public health and safety. Before HEPEX, no one was producing daily, operational hydrological ensemble prediction, while weather forecasters were already using ensemble-based, probabilistic forecasts. Today, in 2014, also thanks to HEPEX, many centres, including ECMWF and NOAA, produce operational, ensemble-based, probabilistic hydrological forecasts. Progress has been made because the hydrological and meteorological communities have reached out, exchanged ideas and worked together. Developments in this area have been possible also thanks to the progress of the quality of the meteorological ensembles.
In this talk, first I will discuss why ensembles are more valuable than single forecasts and briefly review how ensembles are now used in meteorology to estimate the probability distribution function of initial and forecast states. Then I will show how the ECMWF operational ensembles perform, and I will conclude by presenting how we are planning to further improve their performance.

Roberto Buizza

Roberto Buizza



  1. It’d be great after these to post a link of a (youtube?) recording of the talk.

  2. Thomas, on the right hand side we have posted a link to our YouTube channel. There you will find this seminar afterwards and all the other webinars in the series.

  3. A preview of the seminar has now been uploaded (see the post). You are welcome with questions to the speaker already now, please post them here and Roberto will answer them directly or in the talk. You will also be able to ask questions live at the end of the seminar.

  4. Do not forget the seminar tomorrow! Please also note that a new version of the seminar has been uploaded today.

  5. Thank you very much Roberto for a very interesting seminar. If you missed it, here is a chance to catch up with it: https://www.youtube.com/user/HEPEXWebinars

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