Warmer oceans have so far won a “tug-of-war” to fuel a hurricane season that has been more active than originally anticipated.

James Cosgrove, senior modeller for Moody’s RMS, said last week that despite a slow start, 14 named storms have been recorded so far this year with more than two months remaining in the season.

Since then, that number has risen to 16 with Tropical Storm Ophelia struck the US East Coast and Tropical Storm Philippe formed in the Atlantic.

While Bermuda has not yet been dealt a direct hit this year, the island endured glancing blows from Hurricane Franklin and Hurricane Lee in recent weeks.

Mr Cosgrove said that when the season began, the question was how the onset of El Niño, a weather phenomenon that hinders storm development in the Atlantic, would offset record-setting warm surface water temperatures, which fuel storms.

“These factors — one that suppresses storm development and other factors that fuel it — resulted in a preseason forecast for a near-normal season, albeit with greater than normal uncertainty given the season could tip either way if one factor were to exhibit a greater influence over the season,” he said.

So far, he said warmer water temperatures appeared to be “winning this tug-of-war battle”.

“Sea surface temperatures in the North Atlantic remain at record levels, with temperature anomalies in the tropical North Atlantic well above what would be expected during a typical hyperactive hurricane season,” Mr Cosgrove said.

"Despite the National Oceanic and Atmospheric Administration declaring that El Niño conditions were present in early June, there has yet to be a significant atmospheric response.“

He noted a report from Australia’s Bureau of Meteorology that found that the usual coupling of the Pacific Ocean and the atmosphere found in El Niño events had not fully occurred.

“The lack of coupling between the ocean and atmosphere in the Pacific thus far is consequential for hurricane development in the North Atlantic,” Mr Cosgrove said.

“Vertical wind shear, a key inhibitor of hurricane development, is running at near-normal levels across much of the North Atlantic main development region.”

He said revised hurricane forecasts issued by a number of meteorological groups that increased the number and strength of storms expected in the season.

“NOAA’s updated forecast then called for 14 to 21 named storms, six to 11 hurricanes and two to five major hurricanes,” Mr Cosgrove said.

“These expected ranges were centred above the 1991-2020 seasonal averages of 14 named storms, seven hurricanes and three major hurricanes.

“The basin has already reached the lower ends of these ranges with two and a half months to go.”

In terms of Accumulated Cyclone Energy, a measurement based on the strength and duration of tropical storms and hurricanes, he noted the 2023 season is already above the 30 year average.

“The most impactful of these storms was Idalia, which made landfall as a Category 3 major hurricane in the Big Bend region of Florida on August 30,” Mr Cosgrove said.

“Idalia was the first major hurricane to make landfall in Florida’s Big Bend region since record-keeping began in 1842.

“It brought catastrophic storm surge and destructive hurricane-force winds to much of northwest Florida, in particular the Big Bend region, alongside heavy rainfall, and strong winds across Georgia.”

He warned that continued warm surface water temperatures and monsoon activity over West Africa could potentially fuel storm activity in the Atlantic into early October.

“With El Niño set to continue to strengthen in the equatorial Pacific through the remainder of this year, it’s probably only a matter of time before broader-scale patterns become more El Niño-like and conditions become increasingly unfavourable,” he said.

“But the key question is, when? Will the El Niño occur in time to silence the remaining peak weeks of the North Atlantic hurricane season, or might budding tropical systems emerging from West Africa and take advantage of the record-warm temperatures while they have a chance?”