FORT LAUDERDALE, Fla. _ An extra-busy hurricane season may be particularly unwelcome this year, but a major weather forecasting service on Thursday announced an upward revision of its already pessimistic forecast.
AccuWeather said it now expects up to 11 hurricanes this season, including up to four major hurricanes.
The organization has previously predicted seven to nine hurricanes. Although the lower range of the forecast held steady at seven, the organization increased the upper range to 11.
AccuWeather also increased the predicted number of major hurricanes, those with wind speeds of at least 111 mph. The previous prediction called for two to four major hurricanes. The new prediction says to expect four to six.
All the major forecasting organizations have called for above-average seasons this year, citing the warmth of the Atlantic Ocean and atmospheric conditions that should favor the low-wind shear that would allow hurricanes to form.
An average season produces seven hurricanes. The major reason for the change was the growing confidence that this year will bring a La Nina, a cooling of the central Pacific Ocean that can reduce wind-shear over the Atlantic, making it more likely that hurricane could form undisturbed by high-level changes in wind direction that could disrupt their structures.
"New climate model runs show a trend toward La Nina evolving during the second half of the upcoming summer," said AccuWeather Senior Meteorologist Dan Kottlowski, in a report issued by the company. "This would suggest a decrease in the episodes of vertical wind shear, which can limit tropical development and intensification."
Hurricane season begins June 1 and lasts through November, with the peak running from mid-August through October.
Although the initial forecasts agree that a busy season is likely, they will be followed by forecasts just before the season begins and as it starts to peak in August. These forecasts are considered more accurate since they're dealing with the latest information.
"This new information gives us more confidence of the potential _ again, still potential _ for a very active season," he said.
