On the Influence of the Pacific and Atlantic Meridional Modes on Precipitation over the Continental United States

The Pacific Meridional Mode (PMM) and the Atlantic Meridional Mode (AMM) are the first Maximum Covariance Analysis (MCA) modes of sea surface temperature (SST) and surface wind fields in the Pacific and North Atlantic. PMM and AMM strongly modulate tropical cyclone activity in the western North Pacific and the North Atlantic, respectively. However, little is known about the role that PMM and AMM play in controlling precipitation across the continental United States. This study examines the impacts of PMM and AMM in terms of total and extreme precipitation. Analyses will be performed at the seasonal scale over the 1948-2015 period. The physical mechanisms responsible for such influences will also be presented.