Ensemble prediction: past, present and future

Ensemble prediction: past, present and future

Contributed by Fredrik Wetterhall and Roberto Buizza, ECMWF The work of producing meteorological ensemble forecasts started 25 years ago at ECMWF and NCEP, and it sparked a revolution in both weather forecasts and its many applications. To celebrate this occasion, more than 100 people from across the world joined the 28 speakers at ECMWF’s Annual Seminar 11-14 September held in Reading, UK. The theme was “Ensemble prediction: past, present and future” and the four days where filled with presentations and…

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A never-ending struggle – Improving spring melt runoff forecast via snow information

A never-ending struggle – Improving spring melt runoff forecast via snow information

Contributed by David Gustafsson (SMHI), member of the SMHI Guest Columnist Team As long as we can remember, the Swedish hydropower hydrologists have tried to improve the spring melt runoff predictions by integrating snow measurements in their forecast models. Various measurements techniques have been used: traditional snow surveys with snow tube sampling; snowmobile and helicopter borne ground-penetrating radar and gamma-ray sensors; laser-scanning; and of course numerous attempts with satellite data (Photo 1). The usual conclusions have been, “yes we can…

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WhatsApp chat between a forecaster and a modeller in hydrology

WhatsApp chat between a forecaster and a modeller in hydrology

When does a model value become an observation?

When does a model value become an observation?

Posted by @Hydrology_WSL (Massimiliano Zappa) on behalf also of @FPappenberger (Florian Pappenberger), @stagge_hydro (Jim Stagge) and @BteBrake (Bram te Brake). We acknowledge also tweets by @highlyanna (Anne Jefferson) and by @YoungHydrology. This blog post started out of the blue on October 30th 2015 after the twitter timeline of @Hydrology_WSL prompted a post by @highlyanne: She is unfortunately not the only researcher (modeler) confronted with interruption of key “observations” or “sudden changes” in the quality of the “observations” they are using….

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Interactions between data assimilation and post-processing

Interactions between data assimilation and post-processing

I have recently contributed to a paper where we investigate how statistical post-processing and data assimilation (also called real-time model updating in the engineering community) can be intrinsically related in the hydrological forecasting framework. The paper, co-written with François Bourgin (main author), Guillaume Thirel, and Vazken Andréassian, can be found here. We were basically guided by the following questions: How does data assimilation impact hydrological ensemble forecasts? How does post-processing impact hydrological ensemble forecasts? How does data assimilation interact with…

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