US Climate Variability and Predictability Program

Diurnal to Intraseasonal Variability and the Central American Drought

University of Washington
National Autonomous University of Mexico
Session III: Weather and climate extremes in the Americas
Since the summer of 2014 Central America has experienced a prolonged drought throughout most of the region, particularly in Honduras, Guatemala, El Salvador and Nicaragua. The drought has had a significant impact on agriculture, placed more than 2 million people in need of food assistance and impacts the food security of the region. The large-scale atmospheric conditions supporting this drought may be related to the El Niño conditions that have persisted across the tropical Pacific since spring 2014. These conditions have grown stronger in recent months. This study aims to examine the impact of the large-scale tropical atmosphere and SST patterns on the local processes controlling organized convection over Central America and its propagation over the tropical eastern Pacific. We will additionally investigate the interaction of this topographically forced diurnal convection with synoptic waves propagating northwestward along the Pacific coast of Central America, as well as the modulation of these interactions by the large-scale conditions associated with the interannual variability in the region. The study relies on TRMM/GPM rainfall observations, MERRA reanalyses and COCONet total column water vapor measurements across Central America with coverage back to 2002. The goal of this study is to determine if the current observational network is sufficient to monitor the region during extreme weather conditions such as the current drought, as well as to determine if these observations can be used to understand the physical mechanisms responsible for the reduced rainfall over the region.
Presentation file