Intensive Study 5 EI Nino occurs when weather patterns in the tropical Pacific shift violently. Normally, strong westward-blowing trade winds off South America push surface water toward Asia, Just as blowing on hot coffee pushes the liquid up against the opposite side of the cup, the trade winds pile warm water against the coastlines of Australia, Indonesia and the philippines. above the warm water, moist air rises lowering atmospheric pressure and triggering the tropical showers that nourish the rain forests of Asia. Meanwhile high-altitude winds travel back toward south america. there, the cooled air sinks raising atmospheric pressure and suppressing rain along most of the Pacific coast, making it one of the driest regions in the world5 El Niñ o occurs when weather patterns in the tropical Pacific shift violently. Normally, strong westward-blowing trade winds off South America push surface water toward Asia. Just as blowing on hot coffee pushes the liquid up against the opposite side of the cup, the trade winds pile warm water against the coastlines of Australia, Indonesia and the Philippines. Above the warm water, moist air rises, lowering atmospheric pressure and triggering the tropical showers that nourish the rain forests of Asia. Meanwhile high-altitude winds travel back toward South America. There, the cooled air sinks, raising atmospheric pressure and suppressing rain along most of the Pacific coast, making it one of the driest regions in the world. Intensive Study