Quantifying Significant Weather Impacts of Projected Change in Storm Track Activity

Abstract:

In the mid latitudes, storm tracks give rise to much of the high impact weather, including precipitation and strong winds. Thus it is of interest to investigate how storm track activity is projected to change under global warming. Moreover, not only is the projected change in storm track activity of interest, the potential significant weather impacts of such projected change, as well as the spread in projected weather impacts associated with the spread in projected storm track activity due to model and climate uncertainties, are also of interest.

A framework has been developed using statistical pattern correlation and regression to systematically evaluate how well different storm track activity metrics relate to weather impacts, including precipitation and high winds, using storm track activity and weather impacts derived from reanalysis and observational data. Our results show that over many regions, including much of North America and Europe, month-to-month variability in a number of storm track activity metrics can explain a large fraction of the variability in significant weather impacts.

The statistical pattern correlation model derived from reanalysis/observations, as well as from CMIP5/6 historical experiments, can be applied to project storm track related changes in significant weather impacts based on model projected storm track changes under global warming scenarios. This allows us to quantify how the projected change in storm track activity translates into weather impacts, as well as to examine how much of the model-to-model spread in projected changes in significant weather, such as precipitation and high winds, can be explained by model spread in projected changes in storm track activity. Results from these analyses will be presented.