Two and a half months before the 2024 Atlantic hurricane season officially begins, forecasters have already predicted and warned that warm sea surface temperatures in the Atlantic and the development of a La Niña in the Pacific may create a "perfect storm" of the conditions needed for major hurricanes.
Key to the formation of any tropical cyclone（气旋）is the combination of warm ocean temperatures and the absence of what is known as wind shear. Alex DaSilva, a forecaster, explains that wind shear occurs when wind changes direction and speed at different heights in the atmosphere. When there's much wind shear, it essentially knocks over those clouds and prevents tropical systems from really becoming stronger. Besides, hurricanes also need surface water to be at a temperature of 26 degrees Celsius or higher. That warm water, and the warm air just above it, provides fuel for the storm. The record data for February are 1.2 degrees Celsius above normal.
Over periods ranging from three to seven years, the waters of the central and eastern tropical Pacific Ocean alternately（交 替 地）warm and cool as a result of a repeatedly occurring climate pattern called the El Niño-Southern Oscillation（ENSO）. During an El Niño, sea surface temperatures in the eastern Pacific increase, and those warmer temperature s affect the path of the Pacific jet stream, which in turn brings drier, warmer weather to the northern United States and Canada, and wetter conditions to the Gulf Coast and southeast. El Niño reduces the possibility of Atlantic hurricane formation because it lowers hurricane activity and increases wind shear. La Niña has just the opposite effect of El Niño. During the 2023 season, ENSO was in an El Niño phase. By the time the 2024 season starts, it is likely to have shifted fully into a La Niña.
"If a tropical storm system comes into this area, it could rapidly intensify, potentially close to land," DaSilva cautions. "And that's why people need to be on alert and have their hurricane plans ready. Because any system with these kinds of conditions can explode very quickly. That's what we're concerned about."
