Does El Nino / La Nina greatly affect cyclonic activity?
There tend to be fewer Hurricanes in the tropical Atlantic/Caribbean/Gulf during El Nino events. La Nina years however seems to show an increase. El Nino’s tend to increase the amount of wind-sheer blowing west-to-east across the tropical Atlantic; this inhibits hurricanes forming by disrupting the conditions that favour their formation. These winds prevent hurricanes forming their familiar towering cylindrical shape by sheering off their tops or distorting them so much they break-apart. A few hurricanes manage to make landfall, but not as many as in a non El Nino year, or in a La Nina year. La Nina’s on the other hand alter wind patterns so they favour hurricane formation. http://www.cnn.com/NATURE/9909/10/la.nin… It is expected that the current El Nino will be gone by summer 2010, so this year’s Atlantic hurricane season is expected be more active than last years. Research into connections between El Ni
