Current and emerging developments in subseasonal to decadal prediction
Merryfield, William J.; Baehr, Johanna; Batte, Lauriane; Becker, Emily J.; Butler, Amy H.; Coelho, Caio A.S.; Danabasoglu, Gokhan; Dirmeyer, Paul A.; Doblas-Reyes, Francisco J.; Domeisen, Daniela I.V.; Ferranti, Laura; Ilynia, Tatiana; Kumar, Arun; Muller, Wolfgang A.; Rixen, Michel; Robertson, Andrew W.; Smith, Doug M.; Takaya, Yuhei; Tuma, Matthias; Vitart, Frederic; White, Christopher J.; Alvarez, Mariano S.; Ardilouze, Constantin; Attard, Hannah; Baggett, Cory; Balmaseda, Magdalena A.; Beraki, Asmerom Fissehatsion; Bhattacharjee, Partha S.; Bilbao, Roberto; De Andrade, Felipe M.; DeFlorio, Michael J.; Díaz, Leandro B.; Ehsan, Muhammad Azhar; Fragkoulidis, Georgios; Grainger, Sam; Green, Benjamin W.; Hell, Momme C.; Infanti, Johnna M.; Isensee, Katharina; Kataoka, Takahito; Kirtman, Ben P.; Klingaman, Nicholas P.; Lee, June-Yi; Mayer, Kirsten; McKay, Roseanna; Mecking, Jennifer V.; Miller, Douglas E.; Neddermann, Nele; Ng, Ching Ho Justin; Osso Albert; Pankatz, Klaus; Peatman, Simon; Pegion, Kathy; Perlwitz, Judith; Recalde-Coronel, G. Cristina; Reintges, Annika; Renkl, Christoph; Solaraju-Murali, Balakrishnan; Spring, Aaron; Stan, Cristiana; Sun, Y. Qiang; Tozer, Carly R.; Vigaud, Nicolas; Woolnough., Steven; Yeager, Stephen
Date:
2020-06
Abstract:
Weather and climate variations on subseasonal to decadal time scales can have
enormous social, economic, and environmental impacts, making skillful predictions on these time
scales a valuable tool for decision-makers. As such, there is a growing interest in the scientific,
operational, and applications communities in developing forecasts to improve our foreknowledge
of extreme events. On subseasonal to seasonal (S2S) time scales, these include high-impact meteorological events such as tropical cyclones, extratropical storms, floods, droughts, and heat and
cold waves. On seasonal to decadal (S2D) time scales, while the focus broadly remains similar (e.g.,
on precipitation, surface and upper-ocean temperatures, and their effects on the probabilities of
high-impact meteorological events), understanding the roles of internal variability and externally
forced variability such as anthropogenic warming in forecasts also becomes important. The S2S
and S2D communities share common scientific and technical challenges. These include forecast
initialization and ensemble generation; initialization shock and drift; understanding the onset
of model systematic errors; bias correction, calibration, and forecast quality assessment; model
resolution; atmosphere–ocean coupling; sources and expectations for predictability; and linking
research, operational forecasting, and end-user needs. In September 2018 a coordinated pair of
international conferences, framed by the above challenges, was organized jointly by the World
Climate Research Programme (WCRP) and the World Weather Research Programme (WWRP). These
conferences surveyed the state of S2S and S2D prediction, ongoing research, and future needs,
providing an ideal basis for synthesizing current and emerging developments in these areas that
promise to enhance future operational services. This article provides such a synthesis.