Description:

Climate Variability and Change exert powerful effects on global circulation, moisture availability, and the evolution of weather systems. In 2022-3 we have seen the impacts that winter weather can have, such as through the persistence of high-impact snowfall in California, where snow totals have broken records. There is high confidence that climate change is contributing to warmer temperatures, heavy precipitation extremes, drought, and heatwaves. There is less confidence in the effects of climate change on winter weather and its extremes. In recent years, research has focused on understanding how cold air outbreaks may be related to changes in high latitude and stratospheric circulation, and to characterize trends in winter weather severity and frequency in a warming world. There are also questions to be explored in the relationship between winter weather, cold waves, and natural variability; the role of both variability and climate change in future winter weather events; changes in winter storm evolutions, such as their intensity, phase type, and durations; and the ability of global and regional models to adequately simulate cool season dynamics, thermodynamics, and planetary circulations. This session aims to explore a broad array of questions related to these and other research areas that examine cool season phenomena, including both core science research, as well as impacts to society, ecosystems, health, and infrastructure. In 2023, we ran the first session in this topic area which was well received, suggesting that there is much more to be explored in this subject area.