Forecasters say El Nino will play a big role in how active this hurricane season gets. Watch video
Long-range weather forecasters say the formation of another El Nino weather pattern could limit the number of hurricanes and tropical storms that develop in the Atlantic Ocean this year.
The 2017 hurricane season officially gets under way on June 1, but several forecasters have already issued their predictions on how many storms are likely to form.
- AccuWeather forecasters are anticipating a hurricane season that is less active than normal, with 10 named storms, five of which will strengthen into hurricanes. Three of those will become major hurricanes, AccuWeather predicts.
- In their annual hurricane assessment, storm researchers at Colorado State University are also calling for a season that will be slightly below average. They are predicting 11 named storms in the Atlantic this year, four of which will strengthen into hurricanes, and two of those becoming major hurricanes.
- Forecasters at The Weather Channel are predicting a hurricane season that rides right along the historical average for the Atlantic: 12 named storms, 6 becoming hurricanes, and two of those strong enough to be classified as major.
Major hurricanes are those designated as Category 3, 4 or 5 in strength. Category 3 hurricanes pack sustained winds of 111 to 129 mph, Category 4 storms reach 130 to 156 mph and Category 5 storms, which are rare, carry sustained winds of 157 mph or stronger.
Big wildcard
Forecasters from AccuWeather, CSU and The Weather Channel all say the big wildcard this hurricane season is whether a new El Nino weather pattern will develop in the tropical waters of the Pacific Ocean this summer.
When those waters get warmer than usual, the warm air rises into the atmosphere and gets pushed from the west to the east, where it interacts with storm systems that are forming in the Atlantic. Experts say El Nino conditions usually result in more wind shear, which cuts down on the number of tropical storms and hurricanes.
Although it's not yet known whether another El Nino pattern will take shape, hurricane researchers at CSU say there "is the potential that a weak to moderate El Nino could develop by the peak of the Atlantic hurricane season."
Another factor that will play a role in the 2017 hurricane season is the surface water temperature in the Atlantic, the researchers said.
"Most of the North Atlantic has anomalously cooled over the past month, and the tropical Atlantic is now slightly cooler than normal," the CSU researchers said in their Atlantic hurricane outlook. "In addition to providing less fuel for tropical cyclone formation and intensification, cooler tropical Atlantic sea surface temperatures are associated with a more stable atmosphere as well as drier air, both of which suppress organized thunderstorm activity necessary for hurricane development."
Forecasters at The Weather Channel agree El Nino is a major wildcard.
"If El Nino fails to launch, we may be too low with our numbers," said Todd Crawford, chief meteorologist with the weather network.
Rare tropical storm in April
During the past few days, the Atlantic Ocean has shown some signs of tropical activity, with a small subtropical depression forming on Wednesday. On Thursday, it was elevated to a tropical depression, then strengthened into a rare April tropical storm and was named Arlene.
Forecasters say the storm -- only the second tropical storm on record in the Atlantic during the month of April -- is very far out in the ocean and poses no threat to land. Arlene, which had maximum sustained winds of 50 mph late Thursday night, is expected to dissipate on Friday, according to the National Hurricane Center.
UPDATE: In a forecast update issued shortly before 11 a.m. Friday, the National Hurricane Center said Tropical Storm Arlene has weakened to a post-tropical cyclone and is expected to fizzle out by Friday night.
Active hurricane season in 2016
Last year, the Atlantic hurricane season ended with 15 named storms, seven of which became hurricanes and four major ones: Hurricane Gaston (Category 3), Hurricane Otto (Category 3), Hurricane Nicole (Category 4) and Hurricane Matthew (Category 5), the most powerful and deadly Atlantic storm in almost a decade.
Otto, a rare November hurricane that battered Central America, was initially classified as a Category 2, but the National Hurricane Center upgraded its status to a Category 3 earlier this year after reviewing its wind speeds.
Len Melisurgo may be reached at LMelisurgo@njadvancemedia.com. Follow him on Twitter @LensReality or like him on Facebook. Find NJ.com on Facebook.