Assessing the impact of El Niٌo Modoki on seasonal precipitation in Colombia

The influence of the tropical Pacific SST on precipitation in Colombia is examined using a 341 station dataset covering the period 1979–2009. Through a singular value decomposition the two main coupled variability modes show SST patterns clearly associated with canonical El Niño and El Niño Modoki, respectively, presenting great coupling strength with the corresponding seasonal precipitation modes in Colombia. The results reveal that, mainly in winter and summer, canonical El Niño and El Niño Modoki events are associated with a significant rainfall decrease over the northern, central, and western Colombia. The opposite effect occurs in some localities during spring, summer, and autumn. The southwestern region of Colombia exhibits an opposite behavior connected to canonical El Niño and El Niño Modoki events during years when both events do not coexist, showing different seasonal precipitation response to these different patterns. The results found establish the foundations for precipitation modeling in Colombia from the Pacific SST.