NOAA expects an active 2013 Atlantic hurricane season, with three to six major hurricanes in the forecast. On Thursday, NOAA issued their season-long outlook, which lasts from June 1 to November 30.NOAA expects a total of 13 to 20 named storms, well above the average of 12 named storms per season. They also expect seven to 11 of those storms to reach hurricane status, also above the average of six hurricanes per season. Finally, the three to six major hurricanes in the forecast (Category 3 or higher) is also above the average of three major hurricanes per season.
Western Massachusetts saw the effects of tropical systems in each of the last two years, with Tropical Storm Irene moving through the region in 2011 and Superstorm Sandy impacting the area last year.
"As we saw first-hand with Sandy, it's important to remember that tropical storm and hurricane impacts are not limited to the coastline," said Kathryn Sullivan, Ph.D., NOAA's acting administrator, in a statement released on Thursday. "Strong winds, torrential rain, flooding, and tornadoes often threaten inland areas far from where the storm first makes landfall."
NOAA cited three primary climate factors that influenced a higher-than-normal hurricane season.
"These conditions include weaker wind shear, warmer Atlantic waters and conducive winds patterns coming from Africa," said Gerry Bell, Ph.D., lead seasonal hurricane forecaster with NOAA's Climate Prediction Center.
Many hurricanes begin their lifecycle as a storm or disturbance moving west off the African continent into the Atlantic. NOAA said a strong west African monsoon can produce an abundance of these disturbances that enter the Atlantic waters, and create more opportunities for these storms to grow into tropical systems. Warm waters are also critical fuel for hurricane development.
NOAA also does not expect El Nino to develop this summer, which typically suppresses hurricane development due to the stronger wind shear it creates. Wind shear is the differences in wind speed and direction with height. Strong wind shear can effectively tear apart the top of developing storms before they can mature into tropical systems. A lack of El Nino, and a lack of wind shear, is much more favorable for hurricane development.
This forecast does not predict how many of these storms will make landfall. Those effects are forecasted on a storm-by-storm basis. The peak of hurricane season begins in early August.