As the fifth named storm of the season fell apart in the Caribbean Thursday, federal hurricane forecasters rolled out an update their predictions for the rest of what they still say will be an "active" season.
The August outlook calls for a slight increase in the number of storms and hurricanes that forecasters expect, and a considerable boost to their confidence that they're right.
Gerry Bell, lead hurricane season forecaster for the National Oceanic and Atmospheric Administration, said his agency now expects 14 to 19 named storms, up from the 12 to 18 they forecast in May. Of those, seven to 10 could become hurricanes (up from six to 10 in May), and three to five could become Category 3 storms, with winds of 111 mph or more. That's down slightly from the figure of three to six in the May forecast.
NOAA's forecast for an above-average hurricane season comes with an 85 percent confidence factor, up from 65 percent in May. There is a 15 percent chance for an average season.
"There is no expectation it will be below normal," Bell said. That confidence comes from several factors:
• The "multi-decadal signal" in ocean and atmospheric cycles that launched an era of active Atlantic hurricane seasons in 1995. This would be the 12th above-average storm season in the 17 years since.
• "Exceptionally" warm sea-surface temperatures in the tropical Atlantic, now 1 degree above the average, the third-warmest since record-keeping began in 1954.
• The failure of hurricane-suppressing El Nino conditions to develop in the tropical Pacific.
"The atmosphere and Atlantic Ocean are primed for high hurricane activity during August through October," typically the peak months for storm formation, Bell said. "Storms through October will form more frequently and become more intense than we've seen so far this season."
Five named tropical storms have formed since the season began June 1. The fifth, Tropical Storm Emily, was drenching Hispaniola on Thursday with up to 20 inches of rain. But by the afternoon, the National Hurricane Center said the storm had degenerated to a tropical low after its encounter with the island's mountainous interior. Some chance remained that Emily's remnants could reform into a tropical storm over the weekend, forecasters said.
Last year's hurricane season was among the most active on record, with 19 named storms. But none struck the U.S. The last hurricane to strike the U.S. was in 2008. Emergency managers are worried that too many people may not take the threat seriously.
"There is no reason for complacency. Disasters can strike anytime, anywhere. The difference with hurricanes is they have a season. Now is the time for you and your family to be prepared," he said.
Information on how to prepare for the hurricane season is online at http://www.ready.gov .
http://twitter.com/froylanceMaryland weather blog: Frank Roylance on meteorology
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