Emergency evacuations are taking place in Guam and the Northern Mariana Islands as a super typhoon bears down on the US Pacific territories.

Bavi is forecast to make landfall early on Monday morning, with winds of up to 257km/h (160mph), according to the US National Weather Service (NWS).

It warned the “very dangerous” storm could cause “catastrophic” damage, with “significant flooding from torrential rains” possible and waves potentially nearly 11m (35ft) high on Monday.

The western Pacific region is particularly prone to tropical cyclones. While storms of this strength are unusual for the US islands, scientists say climate change is making powerful typhoons more common.

Bavi is expected to pass directly over Guam and the Northern Mariana Islands by Monday afternoon, but the NWS warned that destructive conditions could be expected for eight to 10 hours prior to or after the arrival of the storm’s centre.

“The window is rapidly closing to evacuate if directed to do so by local officials, or if your home is vulnerable to high winds or flooding,” the agency said, adding that winds “will pose a deadly threat to those venturing outside”.

Guam, usually a sun-soaked tourist destination with a population of about 170,000, has opened five evacuation centres in its schools. These sites have a maximum capacity of around 1,700 and are primarily intended for vulnerable people.

The island’s civil defence office said at 13:00 local time (03:00 GMT) on Sunday that one of the evacuation sites had already reached maximum capacity and that people were being redirected to another site.