Emergency evacuations are underway in Guam and the Northern Mariana Islands as a super typhoon hits the US Pacific territories.

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

It warned that the “very dangerous” storm could cause “catastrophic” damage, with possible “significant flooding from torrential rain” and waves potentially almost 11 meters high on Monday.

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

Bavi is expected to pass directly over Guam and the Northern Mariana Islands on Monday afternoon, but the NWS warned that destructive conditions could be expected for eight to 10 hours before or after the storm’s center arrives.

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

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

The island’s civil defense office said at 1:00 p.m. 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.