Cosgrove, who is part of the event response team at the modelling firm, warned costly storms could still occur even though the peak of the season has now passed.
“It’s been a record-breaking season to date with 23 named storms by the end of September,” Cosgrove told The ReInsurer in a video interview. “We still have two full months of the Atlantic hurricane season to go.”
“Some of the revised forecasts put the named storm total up towards 28 which would tie the record set back in 2005.
Sea surface temperatures across the Atlantic remain warm, so we could expect some further impacts in the remainder of the season.
Cosgrove said to expect an uptick in activity as we enter October with the threat of more storms.
“Even though we have passed through the peak of the season costly storms can still happen. In recent years we have seen hurricanes Matthew and Michael impact the US in October,” he said.
Cosgrove said this year’s busy hurricane season had seen the majority of storms become the earliest on record for their respective naming letter.
“Going into the season we were expecting an above average season but many forecasters did not predict quite this level of activity,” he said.
“A lot of comparisons have been made to activity in 2005 which was a devastating year in terms of hurricanes that made landfall.
“We have also had a record nine storms make landfall in the US, which has only occurred once before in 1916.”
Cosgrove said the busy season was in part due to the warm sea surface temperatures across the Atlantic which has provided the fuel for tropical cyclones to intensify.
“In the last few weeks we have moved into a La Nina phase of the El Nino Southern Oscillation,” he said.
This cyclical phase of cooler temperatures in the Pacific can lead to an increase in hurricane activity.
In contrast to the Atlantic, the Pacific basin has seen a quiet year for storm activity.
“The Atlantic has produced more named storms than the rest of the northern hemisphere combined,” Cosgrove said.
With regards to climate change, he said it remains very difficult to attribute an individual storm or season to long-term changes to the climate.
“The exact outcome of those influences is still to be determined by science. There are predictions we may perhaps see an increase in the number of storms that form in a season.
“There are also studies that suggest we may see an increase in intensity in storms, or perhaps a combination of both. But it is very difficult to attribute an individual season to climate change.”