Typhoon Mawar continued to strengthen in the Pacific on Monday as the authorities in Guam urged residents to prepare and remain out of the water.
A typhoon warning was in effect for Guam, a U.S. territory, and Rota, a nearby island, the National Weather Service said. Damaging winds were expected within the next 24 hours, through at least Wednesday night.
Just before 6 p.m. local time, Mawar had maximum sustained winds of about 100 miles per hour, said Brandon Bukunt, a meteorologist with the Weather Service in Guam. He said Mawar had not yet developed a true eye but that it was expected to strengthen to a Category 3 typhoon with sustained winds of 115 m.p.h.
The storm is expected to continue to strengthen and intensify, and forecasts project that it will reach Guam on Wednesday morning.
The biggest impacts of the storm are going to begin Tuesday evening and peak in the overnight hours into Wednesday, Mr. Bukunt said.
As the storm approaches the islands, its winds are “going to pick up,” said Mr. Bukunt, and outer rain bands could bring heavy downpours, increasing the chances of flooding, including in Guam, which is home to Andersen Air Force Base.
The difference between a typhoon and a hurricane is in name only, and based on geography. Typhoon is used for tropical cyclones that develop in the northwestern Pacific and affect Asia. Elsewhere, they are called hurricanes.
“The system can do little wobbles, kind of like a snake going through the grass,” said Patrick Doll, the lead meteorologist of the Weather Service. “It may travel in a general direction, but you’re going to have a wiggle here and there. And the key will be, when does that wiggle occur and at what strength, which will determine if anyone takes a direct hit.”
The Weather Service issued a high surf advisory early Monday, saying that large breaking waves of seven to nine feet are building as Mawar approaches. Officials in Guam have also asked residents to remain out of the water.
Gov. Lou Leon Guerrero of Guam and Rear Adm. Benjamin Nicholson placed the island and its military bases on alert on Saturday for possible destructive winds, according to a statement from the base.
The statement added that “all military installations on Guam are currently securing facilities, and housing residents are urged to commence heavy-weather preparedness efforts.”
Typhoons can form year-round but are most common from May to October.
Mawar, a Malaysian name that means “rose,” is the second named storm in the West Pacific this season. The first, Tropical Storm Sanvu, weakened in less than two days.
Lauren McCarthy and Derrick Bryson Taylor contributed reporting.