The 2015 Atlantic Hurricane Season is officially over and as predicted tropical activity stayed below normal. Overall there were 11 named storms, including four hurricanes, two of which, Danny and Joaquin, became major hurricanes. Although no hurricanes made landfall in the United States this year, two tropical storms, Ana and Billl, struck the northeastern coast of South Carolina and Texas, respectively.
Hurricane Joaquin was the strongest Atlantic hurricane since 2007, topping out just below Category 5 strength on October 3 with 155 mph winds. Joaquin was the second deadliest and second most damaging Atlantic named storm of 2015, causing $100 million in damage in the Central Bahamas, where it lingered for several days. Joaquin’s death toll was 35, with 33 of these deaths occurring from the sinking of the ill-fated cargo ship El Faro. Joaquin is the first Category 4 hurricane since 1866 to impact the Bahamas during the month of October.
For the first time since 1892, a hurricane pounded the Cape Verde islands, when Hurricane Fred intensified to a Category 1 storm with 85 mph winds as it passed through the islands on August 31st. Fred became a hurricane at 22.5°W longitude, the easternmost formation location in the tropical Atlantic for any hurricane on record.
NOAA scientists credit El Niño as the leading climate factor influencing both the Atlantic and Pacific seasons this year. “El Niño produces a see-saw effect, suppressing the Atlantic season while strengthening the eastern and central Pacific hurricane seasons,” said Gerry Bell, Ph.D., lead seasonal hurricane forecaster at NOAA’s Climate Prediction Center. “El Niño intensified into a strong event during the summer and significantly impacted all three hurricanes seasons during their peak months.” Bell said El Niño suppressed the Atlantic season by producing strong vertical wind shear combined with increased atmospheric stability, stronger sinking motion and drier air across the tropical Atlantic, all of which make it difficult for tropical storms and hurricanes to form and strengthen. However, El Niño fueled the eastern and central Pacific seasons this year with the weakest vertical wind shear on record.
– WSAV Meteorologist Matt Devitt