CHARLOTTE, NC (WBTV) - One of the reasons why the seasonal hurricane outlook this year was calling for a below-average hurricane season was because of the anticipated El Nino event which developed as expected.
In short, El Nino refers to the cyclical warming of the South Pacific off the western coast of South America. As that water warms, it then heats the atmosphere residing above it. All that warm air is hoisted into the upper atmosphere and it travels eastward into the Atlantic Basin where tropical cyclones like to form.
We all think of tropical storms and hurricanes as very powerful weather systems and the largest storms on earth. Truth is, they are rather fragile. And they depend on a calm environment to develop and strengthen. When stronger surrounding winds are in the region, or even moderate winds blowing in different directions from top to bottom, it disrupts the delicate circulation attempting to form around the tropical low. We refer to this as wind shear. And the plume of air pouring into the Atlantic Basin from El Nino is really stirring things up. Indeed we have watched several tropical systems try to beat the odds this season, only to fail.
Erika appeared to have the best potential as the ocean temperatures have continued to warm later into the summer season. However, it too is now encountering fierce wind shear along with rough terrain as the storms rolls over Hispaniola and Cuba. It should stay on this track, and if the National Hurricane Center is correct, it appears most likely to be heading into the Gulf, just west of the Florida Coast. Conventional thinking would take Erika northward into the Southeast US and toward the Carolinas around mid to late week next week, but some models are suggesting it stalls. Either way, we have not ramped up rainfall forecasts for our region yet until more is known about Erika's eventual destiny.
As we are inclined to say in this business… stay tuned!