Fredrik Wetterhall has transitioned from working in flood forecasting, an area that was expanding at ECMWF when he joined in 2011, to leading some of ECMWF’s involvement in external projects.
In the late 1990s, he earned a Master of Science degree in environmental and aquatic engineering from Uppsala University in Sweden. The degree course included meteorology and hydrology, as well as more general subjects such as biology, chemistry, physics, and mathematics.
“I wanted to work in applied science, and I had an interest in environmental issues,” Fredrik explains. “I thought this would be a good degree course to study to set me up to work in that area.”
After a stint as a consultant at an environmental firm, he decided to pursue a PhD in hydrology at Uppsala University. “I did something similar to what today is called machine learning: statistical downscaling of precipitation,” he says.
For that study, he used a US reanalysis product, in other words a blend of observations with past short-range weather forecasts, rerun with a modern weather forecasting model, to provide a record of past weather and climate.
Composite maps of normalised mean sea level pressure (MSLP) anomalies for the driest and wettest circulation patterns, classified with a multi-objective fuzzy-rule-based classification method. The method, which was adapted to new regions in Fredrik’s PhD, was applied over three regions in China. (From an article in Water Resources Research by F. Wetterhall et al., 2006, https://doi.org/10.1029/2005WR004573, CC BY 4.0).
Having completed his PhD, Fredrik joined the research department of the Swedish Meteorological and Hydrological Institute (SMHI) in 2006 and conducted a postdoctoral research project on climate impacts in the field of hydrology at King’s College London.
He joined ECMWF in 2011 to continue to apply his expertise in an operational setting. “I find myself more comfortable in doing operational work, such as I was doing at SMHI and then at ECMWF, rather than pure research,” he says.
“I really like to see when research is applied to alleviate the consequences of extreme weather.”
Seasonal and sub-seasonal flood forecasts
When Fredrik joined ECMWF, the European Flood Awareness System (EFAS) of the EU’s Copernicus Emergency Management Service (CEMS) was not yet operational.
In 2011, ECMWF applied to run EFAS and was awarded a contract for it. Fredrik utilised EFAS data in several research projects in which ECMWF participated.
He then helped to develop seasonal flood forecasts based on EFAS. “We developed and tested flood forecasts for this time frame as initially only medium-range forecasts were available,” he says.
His work involved experiments to identify the benefits of longer-range forecasts. A seasonal outlook for EFAS as well as for the Global Flood Awareness System (GloFAS) is now available.
Fredrik then spearheaded a sub-seasonal to seasonal (S2S) hydrometeorological forecasting system for EFAS.
Percentage of ensemble members predicting a low river discharge anomaly (lower than the 3rd percentile of the climatological distributions) on the river Rhine at a location north of Cologne during August and September 2003 for seasonal (SEAS) forecasts and for extended-range (EXT) forecasts (sub-seasonal to seasonal), for different starting dates. River discharge below the 3rd percentile was observed during three periods in August and September 2003, as indicated by the blue bars. The extended-range forecast, due to its more frequent initialisation, had an inherent advantage in predicting low river discharge anomalies compared to the seasonal forecast, making a strong case for its operational adoption.
Fredrik also led the development of being able to archive hydrological EFAS data into ECMWF’s Meteorological Archival and Retrieval System (MARS). He made them available through ECMWF’s Copernicus Climate Data Store (CDS). ECMWF’s Data Store Service now comprises a separate interface, which is the Early Warning Data Store for CEMS.
This work pioneered the archiving of hydrological forecasts and analysis data in MARS, marking a significant milestone in the coordination of activities across departments at ECMWF. It also paved the way for the application of data governance based on World Meteorological Organization (WMO) standards to fire forecasting.
ECMWF is the computational centre for EFAS, GloFAS and the European Forest Fire Information System (EFFIS). Those three operational systems are all part of CEMS and utilise various models for different purposes.
During this time, he also acquired a more journalistic role, becoming the editor of the EFAS Bulletin, which is published every two months.
Fredrik edited the EFAS Bulletin from 2014 to 2020.
Coordinating external projects
Since 2020, Fredrik has increasingly been working more directly with the senior directorate of ECMWF’s Forecasts and Services Department. His task is to coordinate the contributions of the Department to external projects. These initiatives aim to deliver products, tools, and knowledge where they are most needed.
Four years ago, he also conducted a gap analysis to determine where additional personnel were needed. “This helped to focus effort on getting get more funding for particular areas in which additional work had to be done.”
The external projects on which Fredrik now works are mainly part of the EU’s Horizon programme. “I have to make sure that we have the right data and tools and the right people for particular projects,” Fredrik says.
He also writes proposals for involvement in external research projects, manages projects that have been approved, and oversees their execution. Some of these deal with the risks, hazards and impacts of health, fire, floods, or meteorological conditions more generally. Increasingly, they also involve machine learning techniques.
“For example, in the Horizon 2020 EIFFEL project, machine learning was used to evaluate future risks of climate change for floods and fire,” Fredrik explains.
In another project, the Horizon Europe CLIMAAX project, an executable Handbook was created to provide tools for non-experts to perform their own climate risk assessment on a regional scale. “The idea was to move climate change data closer to users. That includes, for example, all the data from the EU’s Copernicus Climate Change Service (C3S), which ECMWF runs, as well as other data.”
In addition to external projects, Fredrik is also involved in internal affairs, such as preparations for meetings of ECMWF’s governing Council or participation in a study of ECMWF’s economic impact.
“The move from being directly involved in projects to managing them has been a challenging but exciting change,” he says. “It means that I do less of the hands-on research and development, but the years of experience working in research have provided me with a perfect background that enables me to fulfil this new role.”