Dear Tom,
Is there any relationship between El Nino and the number and strength of hurricanes in the Caribbean?
— Kevin
Dear Kevin,
There is. During an El Nino event the higher-than-normal water temperatures in the equatorial Pacific translate into to a more southerly and stronger-than-normal jet stream across the U.S. and tropical Atlantic. This has a dampening effect on the number of Atlantic Basin hurricanes because it increases the vertical wind shear (change of wind with height), which tears apart the thunderstorm towers as tropical cyclones develop. There are, of course, some hurricanes during a strong El Nino episode, but overall the tendency is for fewer and weaker storms. During strong El Nino episodes in 1982 and 1997, hurricane activity was well below the norm ofsix, with just two in 1982 and three in 1997. Last season logged just four.
