The storm, which is expected to pass near Hawaii’s Big Island sometime today, has the potential to unleash dangerous flash floods and mudslides, the Central Pacific Hurricane Centre said.
Winds had reached 210 kilometres per hour earlier, making the hurricane a category four storm at the time.
Madeline threatens to disrupt a planned visit by President Barack Obama and other dignitaries to Hawaii for the World Conservation Congress, a major meeting of thousands of delegates, including heads of state, scientists and policy makers.
“On the forecast track, the centre of Madeline will pass dangerously close to Hawai‘i County Wednesday and Wednesday night,” the centre said in its advisory, referring to the Big Island.
Madeline was expected to gradually weaken over the next 48 hours.
Hurricane-force winds extended 40 kilometres from the centre of the storm, while tropical storm-force winds extended out 200 kilometres.
The US weather agency said swells generated by Madeline were expected to affect eastern shorelines, with some strong enough to damage the coastline in the coming days.
Madeline is expected to dump 13 to 25 centimetres of rain on Hawai‘i, with some areas receiving up to 38 centimetres.
The World Conservation Congress is set to take place in Hawaii from Thursday to next Saturday.
Obama is scheduled to address the gathering on its opening day.
- RNZI