Calmer Atlantic hurricane season expected this yearReprints
Earth Networks is predicting a slightly less active 2017 Atlantic hurricane season than in 2016.
The Germantown, Maryland-based weather information provider is forecasting nine to 13 named storms this season, a number that includes Tropical Storm Arlene — a rare April storm and the first in that month since 2003, Julie Gaddy, senior meteorologist, said during Earth Networks’ 2017 Atlantic Hurricane Outlook webinar on Thursday. The Atlantic hurricane season doesn’t officially begin until June 1, according to the National Hurricane Center.
Earth Networks expects three to six hurricanes this season, with two or three major hurricanes, she said.
“This would be slightly below average or close to average,” Ms. Gaddy said.
Earth Networks evaluates factors such as the El Niño and La Niña phenomena and ocean water temperatures in the Atlantic, Gulf of Mexico and Caribbean when making its forecasts, she said. Most of the forecast models are predicting an increasing probability for El Niño conditions developing early to mid-summer.
“El Niño is certainly a negative factor and suggests a quiet season, but there is a little bit of a risk there,” Ms. Gaddy said. “A weaker El Niño or a later onset of the unfavorable wind shear could allow for a near-active season.”
El Niño conditions typically result in below-average storm activity while the opposite is true of La Niña, she said.
“Based on our study of the history, it appears as though near to slightly below-average tropical storm activity would be anticipated as we look through this upcoming summer as we’re most likely going to be heading into El Niño conditions,” Ms. Gaddy said.
“El Niño itself reduces the overall number of storms and the number of hurricanes,” she said in response to a question about whether El Niño conditions make it less likely that a storm will make landfall in the United States this season. “But there’s no clear evidence that it changes the tracks of potential hurricanes. And even in an inactive season, it only takes one storm. Think back to Hurricane Andrew (in 1992). That was not a particularly active season, but it made landfall in South Florida with devastating effects.
“Even if the storm doesn’t actually make landfall, the heavy rain can be a considerable risk as evidenced during Hurricane Matthew” in 2016, Ms. Gaddy continued. “Even well inland, you had considerable heavy rain and resulting flooding. So you don’t have to have a landfall to have serious consequences.”
In 2016, there were 15 tropical storms and seven hurricanes, four of which became major hurricanes.
“One particularly interesting side note was the activity that moved through the Southeastern United States, including early storms in the late May to early June timeframe and then followed by Hurricane Matthew, the strongest storm of the year,” she said.
The 2016 activity was in line with the organization’s forecast, which projected 11 to 15 named storms, five to eight hurricanes and two to four major hurricanes.
“We were anticipating a more active than normal season and that is actually what did occur,” she said.