Saturday, May 21, 2011

NOAA hurricane outlook indicates an above-normal Atlantic season

NOAA weighs in with their annual prediction: The Atlantic basin is expected to see an above-normal hurricane season this year, according to the seasonal outlook issued by NOAA’s Climate Prediction Center – a division of the National Weather Service.

Across the entire Atlantic Basin for the six-month season, which begins June 1, NOAA is predicting the following ranges this year:
  • 12 to 18 named storms (winds of 39 mph or higher), of which:
  • 6 to 10 could become hurricanes (winds of 74 mph or higher), including:
  • 3 to 6 major hurricanes (Category 3, 4 or 5; winds of 111 mph or higher)
Each of these ranges has a 70 percent likelihood, and indicate that activity will exceed the seasonal average of 11 named storms, six hurricanes and two major hurricanes.

“The United States was fortunate last year. Winds steered most of the season’s tropical storms and all hurricanes away from our coastlines,” said Jane Lubchenco, Ph.D., under secretary of commerce for oceans and atmosphere and NOAA administrator. “However we can’t count on luck to get us through this season. We need to be prepared, especially with this above-normal outlook.” Climate factors considered for this outlook are:
  • The continuing high activity era. Since 1995, the tropical multi-decadal signal has brought ocean and atmospheric conditions conducive for development in sync, leading to more active Atlantic hurricane seasons.
  • Warm Atlantic Ocean water. Sea surface temperatures where storms often develop and move across the Atlantic are up to two degrees Fahrenheit warmer-than-average.
  • La Niña, which continues to weaken in the equatorial Pacific Ocean, is expected to dissipate later this month or in June, but its impacts such as reduced wind shear are expected to continue into the hurricane season.
“In addition to multiple climate factors, seasonal climate models also indicate an above-normal season is likely, and even suggest we could see activity comparable to some of the active seasons since 1995,” said Gerry Bell, Ph.D., lead seasonal hurricane forecaster at NOAA’s Climate Prediction Center….

No comments: