There are new warnings that despite predictions of a less than average North Atlantic hurricane season the US still faces a one-in-four chance of being hit by a Category 4 or 5 hurricane this year.

New analysis and forecasts from insurer MS Amlin estimates there is a 27% probability of at least one Category 4 or Category 5 hurricane making landfall during the 2026 season, down from 39% a year ago, as strengthening El Nino conditions suppress Atlantic storm activity.

The findings suggest the threat from the most destructive storms has eased since last year, but the insurer cautioned the threat remains.

The reduction in risk is being driven largely by a sharp fall in the probability of a Category 4 or 5 hurricane striking the Gulf Coast. The probability of a Category 4 or 5 landfall in the Gulf of Mexico region has nearly halved from 19% a year ago, to 10%, the insurer said.

Sam Phibbs, MS Amlin’s head of catastrophe research, said: “A one-in-four chance of a Category 4 or 5 US hurricane landfall is lower than we were seeing a year ago, but it is still far from negligible. It only takes one storm to turn a quiet season into a costly one for communities and insurers.

“While El Nino is expected to dampen hurricane activity, its influence is being partly offset by unusually warm tropical Atlantic waters, which are keeping conditions favourable for storms to form and intensify.”

Florida remains one of the most exposed stretches of coastline, with the chance of a Category 4 or 5 hurricane landfall declining more modestly from 19% last year, to 14%.

The outlook reflects the emergence of El Nino conditions in the Pacific Ocean, which typically increase wind shear across the tropical Atlantic and make it harder for hurricanes to form and intensify. NOAA confirmed the emergence of El Nino in June and expects conditions to strengthen during the second half of the year.

MS Amlin’s mean forecast suggests a below-average Atlantic hurricane season, with 11 named storms, five hurricanes and two major hurricanes, compared with long-term averages of 14.4 named storms, 7.2 hurricanes and 3.2 major hurricanes.

However, the insurer cautioned that lower Atlantic hurricane activity does not necessarily translate into fewer catastrophe losses.

Last year, no hurricanes made landfall in the US despite forecasts pointing to elevated risk. Yet Hurricane Melissa rapidly intensified into a Category 5 storm before striking Jamaica, causing an estimated $8.8 billion of economic damage.

“Where storms make landfall is often more important than how many storms form,” Phibbs added. “A quieter season can still produce significant losses if a major hurricane strikes a highly exposed location.”

Forecasts point to above-average tropical cyclone activity in the Pacific Basin this year as El Nino strengthens.

Tropical Storm Risk predicts 27 tropical storms, 18 typhoons and 11 intense typhoons in the basin, above long-term averages of 26 tropical storms, 16 typhoons and nine intense typhoons.

Phibbs continued: “The Atlantic may be less active, but risk is shifting rather than disappearing, with lower US hurricane activity accompanied by expectations of more active typhoon conditions in the Pacific.”

Florida remains one of the most exposed stretches of coastline, with the chance of a Category 4 or 5 hurricane landfall declining more modestly from 19% last year, to 14%.