WSET.com - ABC132011 Hurricane Outlook by Matt Ferguson

This week is Hurricane Preparedness Week, as the first day of the Atlantic hurricane season begins soon, June 1. Recently NOAA (National Oceanic and Atmospheric Administration) issued their hurricane outlook and they are forecasting an especially active season. The current outlook is for 12 to 18 tropical storms, of which 6 to 10 become hurricanes and 3 to 6 of those become major hurricanes with winds of 111mph or higher. The average numbers are 11 tropical storms, 6 hurricanes and 2 major hurricanes (categories 3 to 5).

You may be wondering. How do meteorologists forecast hurricane development months in advance??? There are various factors to consider, but we'll focus on 3 that affect hurricane formation the most. For years scientists have studied the climate patterns around the equator, called the tropical multi-decadal signal. Since 1995, this has signaled favorable conditions across the Atlantic for hurricane development. And an active environment looks to continue for at least a decade to come. Sea surface temperatures are averaging up to two degrees warmer than usual. As we all know, hurricanes feed off and intensify over very warm water temperatures. Also, we are currently in a La Nina phase. This is when the Pacific Ocean temperatures are cooler than average, causing weaker upper level winds over the Atlantic. When this is the case, hurricanes are not torn apart by powerful winds high in the sky and are able to strengthen. While La Nina weakens this summer, reduced wind shear over the Atlantic will linger until this fall.

Believe or not, 2010 was an extremely active tropical season. There were 12 hurricanes that developed, and remember on average we only see 6. The reason it seemed to be a calm year is because no hurricanes hit the East Coast. We only had one tropical storm strike. That was Bonnie, which made landfall in southern Florida, July 23. The closest one to our region was Hurricane Earl, which at one time had winds of 145mph. This major hurricane passed just to the east of the Outer Banks on September 3, with winds of 115mph. Therefore, you can still have an active hurricane season, with very little impacts. While this year is expected to be more active than normal, hopefully all the storms will remain deep in the Atlantic!