17-21 March 2025
University of Bonn
Europe/Berlin timezone

University of Bonn, main building, copyright: Volker Lannert / University of Bonn

March 17 - 21, 2025 international researchers on observations, numerical models, and hydrology will meet in Bonn, Germany, for the conference Precipitation Processes - Estimation and Prediction (PrePEP). We discuss multi-sensor, new emerging and opportunistic in-situ and remote sensing techniques, which help to better understand and monitor precipitation processes. Central topics of the PrePEP conference are methodologies for exploiting observations for retrievals, nowcasting, data assimilation and parametrization development for NWP models as well as blending and probabilistic techniques towards seamless prediction including hydrological forecasts. A better understanding, assessment and prediction of extreme precipitation events and floods are additional key elements of PrePEP.


If you have any questions please reach out to prepep2025@uni-bonn.de

Important dates

  • June 2024: Next updates (e.g. accommodation advices and invited speakers)
  • 1st of August 2024: Abstract submission opens
  • 29th of September 2024: Abstract submission deadline
  • 10th of October 2024: Acceptance E-mails sent out and program is posted
  • 15th of October 2024: Registration opens
  • 10th of January 2025: Registration deadline

Overview of sessions and their scope

We welcome contributions to the following five sessions, with two sub-sessions each.

Session 1: From Classical to Integrated Remote Sensing

The session invites contributions, which introduce and exploit observational networks for the description, quantification and improved process understanding of clouds and precipitation. This includes e.g. ground- and satellite-based remote sensing techniques as well as in-situ measurements, opportunistic sensors and citizen science contributions. We especially welcome multi-sensor, multi-frequency, (spectral) polarimetry and integrated approaches to improve accuracy or get deeper insights in precipitation generating processes. This session also addresses advanced retrieval and estimation techniques to improve and extend the observational data set with high-level products for further use in e.g. nowcasting and data assimilation.

  • 1.A New observation strategies for clouds and precipitation (multi-frequency, spectral polarimetry, multi-sensor)
  • 1.B New retrieval and estimation techniques (e.g. fusion, Bayesian)

Session 2: Enhancing Process Understanding

A better understanding of precipitation formation processes is key to improving precipitation forecasting. This session focuses on how new observation types and novel techniques of data analysis and data integration are used to evaluate and improve models of precipitation formation. Contributions on enhancing microphysics process understanding and process modeling, model microphysics evaluations, parameterization development and model parameter estimation, either in the framework of classical NWP or modern AI methods, are welcome.

  • 2.A New observations for modeling and parameterization development
  • 2.B Model parameter estimation 

Session 3: Prediction Scales and Model Development

Weather extreme events are becoming more prevalent. An informed decision-making requires sophisticated numerical models which help us to better understand, simulate, and forecast the relevant atmospheric processes. The public demands in particular timely and accurate predictions and warnings of extreme precipitation and hazards such as large hail and severe wind gusts. The session invites contributions on classical or AI-based nowcasting techniques for very small scales and short lead times, integrated nowcasting based on different observation types, and NWP-informed nowcasting down to hectometer scales. Also approaches addressing longer lead times and uncertainty estimation for these techniques are welcome.

  • 3.A Modeling elements in nowcasting 
  • 3.B Hectometer scale modeling for precipitation

Session 4: Seamless Prediction 

Seamless forecasting from minutes to hours and days is of utmost importance to communicate consistent warnings to both individuals and institutions involved in managing high-impact weather related activities. In this session, we welcome contributions to the following topics: convective-scale data assimilation, ensemble generation, predictability analyses, post-processing techniques, blending approaches, and assimilation of new data sources.

  • 4.A Data assimilation integrating nowcasting and new observations
  • 4.B Blending and probabilistic techniques based on nowcasting and NWP ensembles

Session 5: Precipitation and Hydrological Models

The increasing incidents of intense precipitation and related floodings lead to significant socio-economic consequences, while the high spatial and temporal variability of precipitation hampers timely and reliable warnings and limits the accuracy of precipitation modeling and hydrological forecasting. This session invites both the scientific and operational communities to interact towards effective early warning approaches. We welcome contributions on precipitation modeling, analysis of extreme precipitation events, flood simulation and forecasting, uncertainty representation, verification, and the visualization of flood risks.

  • 5.A Extreme precipitation events 
  • 5.B Evaluation, verification and interfaces


The Rhine in Bonn, copyright: Volker Lannert / University of Bonn
University of Bonn
Regina-Pacis-Weg 3, 53113 Bonn, Germany
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