Xuebin Zhang and Olivia Martius, co-conveners and leaders of WCRP's Grand Challenge on Weather and Climate Extremes, would like to bring to your attention an association symposium on high impact weather and climate extremes (M12) at the upcoming 27th International Union of Geodesy and Geophysics (IUGG) General Assembly (July 8-18, Montreal, Canada).


Improved understanding and prediction of weather and climate extremes underpins progress in developing policies and early warning systems that make communities more resilient. Extreme events occur on many temporal and spatial scales so improved prediction exploits sources of predictability on multiple scales that interact across various Earth system components.

This symposium solicits contributions related to observational, synoptic-dynamical, statistical, and modeling studies on high-impact weather and climate extremes. Key challenges include documenting how extremes have varied or are likely to vary under a changing climate and how well climate models capture these events. Presentations that examine the dynamics of extreme events, assess model simulations, track observed extremes, and explore the extent humans are responsible for changes in extremes are all encouraged. Understanding underlying physical and dynamical processes for weather extremes includes diabatic effects on meso- and synoptic-scale dynamics. Simulation, prediction, and scientific understanding of extremes all increase resilience to high-impact weather and are within the scope of this symposium. Contributions on: observing strategies, field campaigns and demonstration projects, dynamical and statistical analysis methods, communicating forecasts and their skill and uncertainties, weather impacts, marine extremes, and assessments of vulnerability and risk are solicited.

Contributions relevant to the World Weather Research Programme project on High-impact Weather (HIWeather) and to the World Climate Research Programme Grand Challenge on Climate and Weather Extremes, including cross-cutting themes, are particularly encouraged. Abstracts integrating hydrological with meteorological extremes are intended for the Joint symposium on Hydrometeorologic and Coastal Extremes in Current and Future Climates (JM04).

The deadline for abstracts is 18 February 2019. Abstract submission and registration are available on the 27th IUGG General Assembly website.