Influence of tropical Pacific SST on seasonal precipitation in Colombia: prediction using El Nino and El Nino Modoki

摘要

In this paper the forecast skill provided by the tropical Pacific Sea Surface Temperature (SST) associated with El Nino and El Nino Modoki over seasonal precipitation in Colombia has been evaluated through a lagged singular value decomposition analysis. The seasonal rainfall in many parts of the country can be predicted with suitable skill using the SST with a lead of one to four seasons. The response of precipitation to different phases of El Nino or El Nino Modoki is consistent with the state of the atmospheric fields of vertical velocity and velocity potential. Winter presents the best results for the prediction model, explaining the greatest percentage of square covariance fraction between the SST and lagged precipitation anomalies. The predictive capacity of these variability modes of SST for rainfall in Colombia is comparable or even higher in some seasons, particularly in winter, than the SST ability to explain the behavior of the precipitation during coe-taneous seasons. The forecast of seasonal precipitation in Colombia validated in this work could be useful for planning and managing natural water resources in some regions of the country, particularly for the driest season of the year.