NOAA raises hurricane season predictionSep 26, 2012
According to NOAA scientists, above normal sea-surface temperatures and storm-conducive wind patterns in the Atlantic will increase hurricane and tropical storm activity this season. This graphic shows major hurricane tracks from 1851 to 2010 in the Atlantic and 1951 to 2010 in the Pacific.
This year’s Atlantic hurricane season is off to a busy start. By mid-August there has been six named storms. According to the updated hurricane season outlook issued by NOAA’s Climate Prediction Center, the remainder of the season is expected to be equally active.
The updated outlook still indicates a 50 percent chance of a near-normal season, but increases the chance of an above-normal season to 35 percent and decreases the chance of a below-normal season to only 15 percent from the initial outlook issued in May.
Across the entire Atlantic Basin for the season — June 1 to Nov. 30 — NOAA’s updated seasonal outlook projects a total of:
• 12 to 17 named storms (top winds of 39 mph or higher), including:
• five to eight hurricanes (top winds of 74 mph or higher), of which:
• two to three could be major hurricanes (Category 3, 4 or 5; winds of at least 111 mph).
The numbers are higher from the initial outlook in May, which called for nine to 15 named storms, four to eight hurricanes and one to three major hurricanes. Based on a 30-year average, a normal Atlantic hurricane season produces 12 named storms, six hurricanes, and three major hurricanes.
“We are increasing the likelihood of an above-normal season because storm-conducive wind patterns and warmer-than-normal sea surface temperatures are now in place in the Atlantic,” said Gerry Bell, Ph.D., lead seasonal hurricane forecaster at the Climate Prediction Center. “These conditions are linked to the ongoing high activity era for Atlantic hurricanes that began in 1995.”
However, NOAA forecasters also announced that El Niño will likely develop in August or September.
“El Niño is a competing factor, because it strengthens the vertical wind shear over the Atlantic, which suppresses storm development. However, we don’t expect El Niño’s influence until later in the season,” Bell said.