By RICARDO WELLS
Tribune Staff Reporter
IF newly updated weather projections hold true, this year’s Atlantic Hurricane Season would be the least active period since 1997, according to international weather experts.
According to AccuWeather’s senior meteorologist and lead hurricane forecaster Dan Kottlowski, storm developments remain few and far between due to the strength of this year’s El Nino forecast and the surface water temperatures across the Atlantic.
This comes as the United States’ Climate Prediction Centre adjusted its 2015 Atlantic Hurricane Season Outlook to a 90 per cent chance of a below-normal hurricane season.
That projection is 20 per cent higher than projections given in May.
Mr Kottlowski indicated that on average, the strength of El Nino determines the wind shear over the tropical Atlantic basin.
“The stronger the system, the stronger the shear, the less of a chance for a storm to develop. A strong vertical wind shear and an enhanced sinking motion across the tropical Atlantic and Caribbean Sea, are now present,” he said.
“These conditions make it difficult for storms to develop.”
He explained that the upper level wind flow, which is often experienced off the coast of Africa during this time of year, is being compressed and restricted by the heavy pressure being pushed down into that region by the El Nino belt.
The El Nino belt stretches from the southwest Caribbean to the coast of Africa, the area considered as the Atlantic basin.
Mr Kottlowski noted that the second factor contributing to the weak season is the below average surface water temperatures.
A tropical system typically needs water temperature of 82 degrees or above to develop and strengthen.
However, Mr Kottlowski said experts have seen below average temperatures across the Atlantic region, another trend he predicted will carry throughout the rest of this season.
At the onset, the US’ National Oceanic and Atmospheric Administration (NOAA) projected a slow season.
NOAA has in recent months made some changes to its projections for this year’s storm season, as they now expect six to 10 named storms, down one from the original projection of six to 11.
Originally, experts indicated that three of those storms would reach hurricane intensity. The projection remains virtually unchanged with officials now expecting one to four storms to reach hurricane intensity.
In addition to those changes, experts have decreased their major storm projections – storms of category three or higher – from two to one.
Mr Kottlowski added that while the changes in projections might signal a weaker than expected season, he warned that there are still three months remaining in this year’s season.
“In 1997 we had a strong El Nino and a weak season. That seems to be the case again this year.
“Projections show that this would be a slow year but that doesn’t mean it should be overlooked,” he added.
To date, there have been three named storms – Ana, Bill, and Claudette.
Ana made landfall in South Carolina in the US in May, and Bill made landfall in Texas in June.
The Atlantic hurricane season runs from June 1 through November 30.