El Niño’s return has countries in Central America on high alert as dry weather conditions are expected to depress crop yields, kill livestock, and shrink water reservoirs, creating socioeconomic pressures that could exacerbate emigration from the region. The U.S. National Oceanic and Atmospheric Administration said in June that the El Niño weather pattern had begun to form, triggered by higher-than-average sea surface temperatures in the equatorial Pacific Ocean. The impact has already been felt by farmers, energy producers and even shippers.