Colorado State University released its annual forecast for the Atlantic Hurricane season earlier this month. One of the biggest factors in predicting how active a hurricane season can be is the ENSO (El Niño Southern Oscillation) pattern.
During a neutral ENSO pattern the sea surface temperatures in the western Pacific ocean warm. This allows the Easterly Trade Winds to stay strong, which helps minimize vertical wind shear (the change in wind direction or speed with height). Low wind shear environments are more favorable for hurricanes to develop in because wind shear can “tear” a hurricane apart.
During an El Niño pattern the sea surface temperatures over the central and eastern Pacific begin to warm. The Easterly Trade Winds will then weaken, as the Pacific Tropical Jet Stream strengthens. The Pacific Tropical Jet moves from west to east, over the Caribbean and Atlantic, creating a higher wind shear environment. This makes it harder for tropical storms to develop in this region.
Right now a neutral pattern is persisting, but there are some indications that a weak El Niño will develop this summer. If that occurs, it could lead to a quieter Atlantic hurricane season.
Remember, even in a “quiet” season hurricanes do still occur. Make sure you prepare before the season gets under (The Atlantic hurricane season officially begins June 1st).