WCRP Workshop on Extremes in Climate Prediction Ensembles (ExCPEns)




The WCRP Workshop on Extremes in Climate Prediction Ensembles (ExCEPns) was held online from 25th to 28th October 2021 sponsored by Asia-Pacific Network for Global Change Research (APN), WCRP, Pusan National University, and APEC Climate Center. The focus of the workshop was to exploit subseasonal, seasonal, annual to decadal and longer-term prediction ensembles to improve the prediction and understanding of extreme weather and climate events. There were 42 oral talks and 31 poster presentations in six sessions.


Weather and climate extremes have enormous impacts on society, and are becoming more severe and frequent as the world warms. Associated risks of heat waves/cold spells, droughts/floods, wind and other extremes are continually evolving in response to climate variations superimposed on forced climate changes. By providing many realizations of climate-system evolution from observation-based initial conditions, climate prediction ensembles offer a powerful tool to better quantify these risks, delineate possibilities for unprecedented extremes, and understand the underlying physical mechanisms and attribution of such events.


I Theme

ㆍ Subseasonal · Seasonal · Annual to Decadal · Multi-Decadal


I Period & Venue

ㆍ 25 - 27 October 2021 WCRP Workshop on ExCPEns (Online)

ㆍ 27 - 28 October 2021 ECS Discussion and Training Program (Online)


I Hosted by

ㆍ APEC Climate Center

Institute for Basic Science (IBS) Center for Climate Physics (ICCP)

Pusan National University

I Organized by

WCRP Working Group on Subseasonal to Interdecadal Prediction (WGSIP)

WCRP Grand Challenge on Weather and Climate Extremes

WWRP/WCRP Subseasonal to Seasonal Prediction Project (S2S)


I Funded by

Asia-Pacific Network for Global Change Research (APN)

World Climate Research Programme (WCRP)

ㆍ Research Center for Climate Sciences, Pusan National University

APEC Climate Center (APCC)

I Workshop Materials

ㆍ Trello link : https://trello.com/b/0h9RHCb4/wcrp-excpens-workshop-2021

ㆍ Video clips : APEC Climate Center Youtube Channel


1. Workshop on ExCPEns

I Opening

Opening Remarks - Dr. Won-Tae Kwon, Executive Director, APEC Climate Center

Opening Remarks - Prof. Kyung-Ja Ha, Research Center for Climate Sciences, Pusan National University

Opening Remarks - Dr. Helen Cleugh, World Climate Research Programme (WCRP)

Opening Remarks - Dr. William Merryfield, Co-Chair of Working Group on Subseasonal to Interdacadal Prediction (WGSIP), WCRP

I Session I. Identification of extremes in observations and climate prediction ensembles

Chaired by Dr. Xuebin Zhang, Co-Chair of WCRP/GC-Extremes & Dr. Arun Kumar, WCRP/WWRP/S2S

Identifying and characterizing spatio-temporally connected extreme precipitation events - Danielle Touma (University of California, Santa Barbara)

ㆍ Using high-resolution PRIMAVERA climate model ensembles to create a European windstorm event set - Julia Lockwood (Met Office Hadley Centre)

Evaluation of the CMIP6 multi-model ensemble for climate extreme indices - Yeon-Hee Kim (POSTECH)

ㆍ Biogeochemical signatures of the North Pacific Blob - Samuel Mogen (University of Colorado Boulder)

ㆍ Predicting temperature and precipitation extremes on decadal to multi-decadal timescales - Markus Donat (Barcelona Supercomputing Center)

ㆍ Seasonal Prediction of European summer heatwaves - Chloe Prodhomme (University of Toulouse, Meteo-France)


I Session II. Physical mechanisms of extremes in observations and climate prediction ensembles

Chaired by Dr. June-Yi Lee, Co-Chair of WCRP/WGSIP, Dr. Doo-Young Lee, Research Center for Climate Sciences

Understanding and predicting the 2019 Antarctic spring polar vortex warming and its impacts - Eun-Pa Lim (Australian Bureau of Meteorology)

Skillful seasonal prediction of North American summertime heat extremes - Liwei Jia (NOAA GFDL/UCAR)

Local and remote drivers of southeast Australian drought - Chiara Holgate (Australian Bureau of Meteorology)

MJO impacts on precipitation extremes over the western U.S.: seasonality and QBO modulation - Jiabao Wang (University of California, San Diego)

Dynamics of modes of large-scale variability and extremes - Christian Franzke (IBS Center for Climate Physics)

Modeling heat-wave intensity conditional on dynamical and thermodynamical forcing - Joel Zeder (ETH Zurich)

The summertime climate extremes over Asia in ultra-high resolution CESM and their responses to CO2 forcing - Zhen Liu (Pusan National University)

Summer temperature response to extreme soil water conditions in the Mediterranean transitional climate regime - Stefano Materia (Euro-Mediterranean Center on Climate Change) 


I Session III. Regional climate extreme information relevant to impacts, vulnerability and adaptation

Chaired by Dr. Yun-Young Lee, APEC Climate Center

Future changes in precipitation extremes over Pakistan using the NEX-GDDP high-resolution daily downscaled data-set - Syed Ahsan Bokhari (Pakistan Meteorological Department )

The application of ensemble seasonal forecasts of extremes for decision-making in agriculture - Debbie Hudson (Australian Bureau of Meteorology)

Using climate variabilities to estimate flood economic loss risk - Xinjia Hu (Max Planck Institute for the Physics of Complex Systems)


I Session IV. Prediction and predictability of large-scale climate variability relevant to extreme events

Chaired by Dr. William Merryfield, Co-Chair of WCRP/WGSIP & Dr. Hongli Ren, WCRP/WGSIP

Wintertime impacts of the 2019 super IOD on East Asia - Takeshi Doi (JAMSTEC)

Sources of subseasonal prediction skill for heatwaves over the Yangtze River Basin revealed from three S2S models - Pang-Chi Hsu (Nanjing University of Information Science & Technology)

Long-term potential predictability of regional extreme events in East Asia estimated from a high-resolution large ensemble - Yukiko Imada (Japan Meteorological Agency)

How well does Met Office seasonal forecast system predict Western North Pacific Tropical Cyclones? - Xiangbo Feng (University of Reading)

Predictability of the Indian Summer Monsoon and representation of associated teleconnections in NCMRWF coupled model - Ankur Gupta (NCMRWF, MoES, India)

Applying the WMO Annual to Decadal Multi-Model Ensemble to Predicting Climate Hazards and Extremes - Leon Hermanson (Met Office, UK)

Decadal Predictability of German Bight Storm Activity - Daniel Krieger (Helmholtz-Zentrum Hereon)


I Session V. Prediction and predictability of specific extreme events (>10 days)

Chaired by Dr. Yukiko Imada, Japan Meteorological Agency & Dr. Frederic Vitart, Co-Chair of WCRP/WWRP/S2S

Advances in the subseasonal prediction of extreme events - Hera Kim (Seoul National University)

Monitoring Global Tropical Cyclone Activities in Weeks 1-4 - Tzu-Ting Lo (Central Weather Bureau, Chinese Taipei)

A dynamical forecast-machine learning hybrid system for lightning prediction - Daehyun Kim (University of Washington)

Seasonal hydrological ensemble forecasts for Australia -prediction of hydrological extremes - Elisabeth Vogel (Australian Bureau of Meteorology)

Subseasonal forecasts of the northern Queensland floods of February 2019: Causes and forecast evaluation - Wayne Yuan-Huai Tsai (National Taiwan University)

S2S prediction ahead of hydro-meteorological events in Southeast Asia during July 2020 - Thea Turkington (Meteorological Service Singapore)

Real-time Extended Range Prediction of Heat Waves over India - Raju Mandal (Indian Institute of Tropical Meteorology)

Evaluating predictions of Indian monsoon low-pressure systems by Subseasonal-to-Seasonal prediction models - Akshay Deoras (University of Reading)


I Session VI. Quantifying current and future risks of climate extremes

Chaired by Prof. Dae-Hyun Kim, University of Washington & Dr. Eun-Pa Lim, Australian Bureau of Meteorology

Quantifying the risk of extreme events with rare event algorithms in climate models - Francesco Ragone (Royal Meteorological Institute of Belgium)

Assessing the current chance of unprecedented dry conditions over North Brazil during El Nino events - Gillian Kay (Met Office, UK)

Climate Model-Based Assessment of Anthropogenic Influence on the 2015-19 Western Cape Drought - Jonghun Kam (POSTECH)

Extreme ENSO events in Copernicus seasonal hindcasts - William Merryfield (Environment and Climate Change Canada)

Projected changes in extreme precipitation in a 60-km AGCM large ensemble and their dependence on return periods - Ryo Mizuta (Meteorological Research Institute, Japan)

Increasing anthropogenic greenhouse gas influence on intensification of extreme precipitation - Seungmok Paik (Yonsei University)

Mean and extreme precipitation associated with Atmospheric Rivers in response to greenhouse warming - Arjun Nelikkattil (IBS Center for Climate Science)

The state of the drought in Africa from the historical and climate change perspective - Asmerom Beraki (Council for Scientific and Industrial Research)

Has the risk of a 1976 north-west European summer drought and heatwave event increased since the 1970s due to climate change? - Laura Baker (University of Reading)

Future changes in tropical cyclone densities and ocean effects due to anthropogenic greenhouse warming - Jung-Eun Chu (IBS Center for Climate Physics)

I Poster Session

Chaired by Dr. Christian Franzke, IBS Center for Climate Physics & Dr. Jung-Eun Chu, IBS Center for Climate Physics & Dr. Yun-Young Lee, APEC Climate Center

[ Session I ]

Characterisation of Compound Soil Moisture - Precipitation Events Over India - Ashish Manoj J (Indian Institute of Technology Roorkee)

Greenhouse gas and aerosol contributions to the observed global and regional changes in extreme temperature during 1951-2015 - Min-Gyu Seong (POSTECH)

[ Session II ]

Multi-year drought storylines for Europe and North America - Claudia Gessner (ETC Zurich)

Changes in the maintenance mechanisms of heat waves over inner East Asia over the last few decades - Qiyun Ma (University of Hamburg)

A cloud model study of internal gravity wave breaking atop a high shear supercell in US High Plains - Salauddin Mohammad (Academia Sinica)

Extreme events in summer 2018 - Wan-Ling Tseng (Academia Sinica)

Hot Extremes over India and their Driving Mechanisms - Manish Joshi (Indian Institute of Tropical Meteorology)

Extreme Precipitation Change in East Asian Spring and Mei-yu Seasons in Global Warming Simulations from High-Resolution AGCMs - Chao-An Chen (Academia Sinica)

NMME-based assessment of the prediction skill of spring precipitation over East Asia and associated oceanic conditions - Byeong-Hee Kim (POSTECH)

[ Session III ]

Assessment of 21st century changing sea surface temperature, rainfall, and sea level patterns in the tropical Pacific Islands using CMIP6 greenhouse warming projections - Laxmikant Dhage (University of Hawaii at Manoa)

[ Session IV ]

Investigating the Predictability of Connected Extremes - Erin Towler (National Center for Atmospheric Research)

Seasonal to decadal predictions with MIROC6 - Takahito Kataoka (JAMSTEC, Japan)

Improved ocean seasonal forecasts using altimetry (sea surface height) data assimilation - Matthew Widlansky (University of Hawaii at Manoa)

Potential Predictability of the MJO during Easterly and Westerly Phases of the QBO - Chalachew Kindie Mengist (Pusan National University)

The impacts of the deforestation on the variability of moisture transport from the Amazon forest to the southeastern of Brazil - Murilo Lemes (National Institute for Space Research, Brazil)

Tropical Cyclogenesis Prediction in the Arabian Sea - Farah Ikram (Pakistan Meteorological Department)

[ Session V ]

The predictive skill of neural network models for Lorenz-6 systems in an ensemble framework - Seoleun Shin (Chonnam National University)

Evaluation of the NCEP 16-day ensemble forecast system for predicting tropical cyclone activity in the Philippines - Marcelino Villafuerte (Philippine Atmospheric, Geophysical and Astronomical Services Administration)

Week 2-3 probabilistic forecasts of extreme precipitation events over Taiwan using Analog Post-processing - Hui-Ling Change (Central Weather Bureau, Chinese Taipei)

Why was Australia not wet in spring 2020 despite La Nina? - Eun-Pa Lim (Australian Bureau of Meteorology)

Are multiseasonal forecasts of atmospheric rivers possible? - Kai-Chih Tseng (Geophysical Fluid Dynamics Laboratory, NOAA)

Machine Learning provides substantial improvements to county-level fire weather forecasting over the western United States - Rackhun Son (Gwangju Institute of Science and Technology)

[ Session VI ]

A new and simple framework for studying risks connected to heavy rainfall - Rasmus Benestad (The Norwegian Meteorological Institute)

Climate change response in wintertime widespread fog conditions over the Indo-Gangetic Plains - Dipti Hingmire (Indian Institute of Tropical Meteorology, Pune)

The DWD Climate Prediction Website - Birgit Manning (Deutscher Wetterdienst, DWD)

Response of July 2020 Heavy Rainfall event to d4PDF 4K warming in Western Japan - Sridhara Nayak (Kyoto University)



2. ECS Training Program

I Session I. Extreme detection and prediction

Chaired by Dr. William Merryfield & Dr. June-Yi Lee, Co-Chairs of WCRP/WGSIP

Detection of extreme events using Machine Learning - Dr. Sookyung Park (Palo Alto Research Center)

Extreme event attribution - Dr. Megan Kirchmeier-Young (Environment and Climate Change Canada)

Predictability of extreme events in S2S time scale - Dr. Frederic Vitart (ECMWF)


I Session II. Projection of future climate extremes

Chaired by Dr. William Merryfield & Dr. June-Yi Lee, Co-Chairs of WCRP/WGSIP

How to use the AR6 WGI interactive Atlas for climate change studies - Prof. Jin-Ho Yoon (Gwangju Institute of Science and Technology)

Low likelihood high impact events assessed in AR6 WGI Chapter 4 - Prof. Erich Fischer (ETH Zurich)

Change of extremes assessed in AR6 WGI Chapter 11 - Dr. Xuenin Zhang (Environment and Climate Change Canada)



| Scientific Organizing Committee

June-Yi Lee (Pusan National University/ICCP, Co-chair of WCRP/WGSIP)

William Merryfield (Environment and Climate Change Canada, Co-chair of WCRP/WGSIP)

Doug Smith (UK Met Office, WCRP/Explaining and Predicting Earth System Change)

Frédéric Vitart (ECMWF, Co-chair of WCRP/WWRP/S2S)

Xuebin Zhang (Environment and Climate Change Canada, Co-chair of WCRP/GC-Extremes)

Arun Kumar (NOAA, WCRP/WWRP/S2S)

Hongli Ren (China Meteorological Administration, WCRP/WGSIP)

Catherine Michaut (IPSL/UVSQ, WCRP)

Yun-Young Lee (APCC)


| Local Organizing Committee

Jin-Ho Yoo (APCC)

Sangwon Moon (APCC)

June-Yi Lee (Pusan National University/RCCS & ICCP, WCRP/WGSIP & WCRP/EPESC Lighthouse Activity)  

| Workshop Materials

· Presentation files for oral and poster presentations can be downloaded at the following link;

☞ Trello Link: https://trello.com/invite/b/0h9RHCb4/f424532880336cb2aa9169198b0fb85d/wcrp-excpens-workshop-2021

  · Presentation clips are available at APCC Youtube Channel

☞ APCC Youtube Link: https://www.youtube.com/watch?v=tT-mJulryho&list=PLGUa1D7J0MXbFLqO3O4OMOGcDoAko9iY2


| Program & Abstract Book