Collaboration of the Weather and Climate Communities to Advance Subseasonal-to-Seasonal Prediction

Abstract

| iv) Utilization of subseasonal and seasonal predictions for social and economic benefits.These are particularly promising areas of research that will greatly accelerate realizing the common goals of WWRP and WCRP and in turn any Earthsystem prediction initiative that would embrace our research (Nobre 2010;Shapiro et al. 2010;Shukla et al. 2010). The advance of predictive skill of weather/ climate EPSs, promoted by the first of the four areas of collaboration, will depend crucially on progress in the other three areas. These are the most pressing issues to solve before achieving optimal utilization of EPSs and their applications. Because they lie at the intersection of weather and climate, these research priorities require the multidisciplinary, collaborative approach promoted by an Earth-system prediction initiative. SEAMLESS WEATHER/CLIMATE EPSS.A fundamental principle of seamless prediction is that the Earth system 1 exhibits a wide range of dynamical, physical, biological, and chemical interactions involving spatial and temporal variability continuously spanning all weather/climate scales. The traditional boundaries between weather and climate are artificial (Shapiro et al. 2010).As explained in Hurrell et al. (2009), for example, the slowly varying planetary-scale circulation preconditions the environment for the "fast acting" microscale and mesoscale processes of daily highimpact weather and regional climate. As an example, there is evidence that natural climate variations, such as ENSO and the North Atlantic Oscillation (NAO)/ northern annular mode, significantly alter the intensity, track, and frequency of extratropical and tropical cyclones and also affect decadal variability in tropical cyclones and the multidecadal drought in the Sahel region. Conversely, small-scale processes have significant upscale effects on large-scale circulation and on the interactions among the components of the global climate system.The challenge facing our scientific community is to improve the prediction of the spatial-temporal continuum of the interactions among weather, climate, and the Earth system. The most important aspect of the challenge is the chaotic nature of weather and climate predictability that needs to be characterized with probabilistic information.EPSs are widely used for weather and environmental (e.g., hydrological) prediction by operational services. Ensemble forecasts offer not only an estimate of the most probable future state of a system, but also a range of possible outcomes. Assessing how climate subseasonal-to-seasonal variations may alter the frequencies, intensities, and locations of highimpact events is a high priority for decision making. Many users are risk averse-more concerned with the probability of high-impact events than with the most probable future mean state. This makes the AFFILIATIONS: brunet-meteorological research division, environment Canada, dorval, Quebec, Canada; Shapiro-national Center for atmospheric research, boulder, Colorado, and Geophysical institute, university of berge...

CFSv2-based sub-seasonal precipitation and temperature forecast skill over the contiguous United States

“…In fact, sub-seasonal forecast information can be useful for developing strategies for proactive natural disaster mitigation (Brunet et al, 2010;Vitart et al, 2012). Previous studies have evaluated the potential of sub-seasonal to seasonal forecasts for heat wave forecasting (e.g., Hudson et al, 2011a;White et al, 2014), hydrological forecasting (e.g., Orth and Seneviratne, 2013;Yuan et al, 2014), water resources management (e.g., Sankarasubramanian et al, 2009), hydropower production management (e.g., Garcia-Morales and Dubus, 2007), and crop yield predic-tion (e.g., Hansen et al, 2006;Zinyengere et al, 2011).…”

“…Previous studies have evaluated the potential of sub-seasonal to seasonal forecasts for heat wave forecasting (e.g., Hudson et al, 2011a;White et al, 2014), hydrological forecasting (e.g., Orth and Seneviratne, 2013;Yuan et al, 2014), water resources management (e.g., Sankarasubramanian et al, 2009), hydropower production management (e.g., Garcia-Morales and Dubus, 2007), and crop yield predic-tion (e.g., Hansen et al, 2006;Zinyengere et al, 2011). Due to the improvement of numerical models, prediction techniques, and computing resources, there is an increasing focus on sub-seasonal forecasts (e.g., Toth et al, 2007;Vitart et al, 2008;Brunet et al, 2010;Hudson et al, 2011bHudson et al, , 2013Robertson et al, 2014).…”

Impact of ocean model resolution on CCSM climate simulations

“…One of the consequences of this unified or seamless approach is the need to explore much higher spatial resolution in weather and climate models. This is done to better resolve features, and, more importantly, because capturing the interactions between the various physical and dynamical processes demands this increase in resolution (Randall et al 2003;Hurrell et al 2009;Shukla et al 2008;Brunet et al 2010). It is also recognized that interactions across time and space scales are fundamental to the climate system itself.…”

Multi-model MJO forecasting during DYNAMO/CINDY period

“…Through upscale/downscale modulations and tropical-extratropical tele-connection, the MJO also influences global weather and climate variability (Donald et al 2006). The recurrent nature of the MJO with a period of 30-60 days offers an opportunity to bridge the forecasting gap between medium-range weather forecast (*1 week) and seasonal prediction (longer than 1 month) (e.g., Waliser 2006;Fu et al 2008;Brunet et al 2010;Hoskins 2012). Most global operational and research weather/climate models, however, still face a variety of challenges to realistically simulate and accurately predict the MJO (Lin et al 2006;Vitart et al 2007;Wang and Seo 2009;Gottschalck et al 2010;Rashid et al 2010;Weaver et al 2011;and Matsueda and Endo 2011), therefore, severely hindering the extended-range TC forecasting (Belanger et al 2012;Fu 2012) and the prediction of MJO's global impacts (Vitart and Molteni 2010).…”