Abstract: Changes in the frequency or intensity of midlatitude weather extremes, such as cold spells, heat waves, or heavy precipitation, in a warming climate are associated with changes in atmospheric circulation and moisture transport. In this talk, I will first present a framework for the dynamic and thermodynamic mechanisms over the full probability distributions of precipitation using a quantile-conditional moisture budget. It is shown that the thermodynamic effect, due to increased atmospheric moisture, is relatively uniform spatially and across the probability distribution of precipitation events. In contrast, the dynamical effect, due to changes in intensity and location of weather systems, varies spatially and between intensities. Then, I will present results on what controls the large-scale circulation conditions for midlatitude circulation, with a focus on jet stream meandering. The implications for extreme moisture transport as well as temperature extremes are also discussed.
For those outside the department, please email Lynn Persing (lak6@psu.edu) for the webinar link.