Intensive Study 6 But with El Nino, the pattern reverses. Atmospheric pressure in the Western Pacific rises, setting the stage for drought from Australia to India. the trade winds decrease, or in extreme years reverse to blow eastward. as a result a huge mass of warm water flows back toward South America, causing storms from Chile to California Meanwhile, over the Pacific, ten-mile- high storm clouds further heat the atmosphere, fueling a stronger-than-normal iet stream, which often splits in two. One branch moves north, warming the Pacific Northwest, central Canada and alaska. Another branch surges south producing heavy rains in the U.S. Gulf States and Southwest6 But with El Niñ o, the pattern reverses. Atmospheric pressure in the Western Pacific rises, setting the stage for drought from Australia to India. The trade winds decrease, or in extreme years reverse to blow eastward. As a result, a huge mass of warm water flows back toward South America, causing storms from Chile to California. Meanwhile, over the Pacific, ten-mile-high storm clouds further heat the atmosphere, fueling a stronger-than-normal jet stream, which often splits in two. One branch moves north, warming the Pacific Northwest, central Canada and Alaska. Another branch surges south, producing heavy rains in the U.S. Gulf States and Southwest. Intensive Study