MANILA, Philippines—A tropical storm with chances of becoming a supertyphoon is threatening to enter the Philippines within the next 48 hours, the state weather bureau said Tuesday.

The storm, with the international name “Haiyan” will be locally named “Yolanda” once it enters the Philippine area of responsibility, Rene Paciente of the Philippine Atmospheric Geophysical and Astronomical Services Administration said.

But the Hawaii-based Joint Typhoon Warning Center had already categorized Haiyan as a typhoon.

“Due to very favorable environmental conditions, rapid intensification is forecast over the next 48 hours with a peak intensity of 130 knots (240.76 kilometers per hour),” according to a forecast by the JTWC.

The JTWC, an agency of the US Department of Defense, categorizes storms with wind speeds of 241 kph as supertyphoons. Pagasa uses no such classification officially.

Yolanda will affect Southern Luzon, Visayas region and Northern Mindanao especially Samar and Leyte provinces. It was forecast to develop into a typhoon before it enters the Philippines.

Paciente also considered the possibility that a storm Signal No. 4 may be raised in areas that will be directly affected by the incoming cyclone.

“It has chances of intensifying before it enters the country because it is still over the ocean,” he said.

“It will cut through Visayas and exit through Mindoro. If it maintains its westward track, it has a low chance of hitting Metro Manila. But it may also go west-northwest,” he said.

It “will then weaken as it tracks across the Philippine islands but should emerge over the South China Sea at near 115-knot intensity (212.98 kph).”

Pagasa uses a different method in calculating wind speeds, and its numbers tend to be more conservative than the JWTC’s.

Yolanda will exit the Philippines by Sunday through Mindoro.

Local disaster agencies also went on alert as it braced for Haiyan, National Disaster Risk Reduction and Management Council spokesman Major Rey Balido said.

The NDRRMC headquarters, meanwhile, has not yet lifted its red alert status since the Bohol quake and All Saints Day.

The local Office of Civil Defense in Northern Mindanao, Caraga, Visayas region, Bicol, Mimaropa, Calabarzon and Metro Manila have already been informed to prepare, Balido said.

“Mimaropa (Oriental and Occidental Mindoro, Marinduque, Romblon and Palawan) will experience cloudy skies with moderate to occasionally heavy rains and thunderstorms, which may trigger flashfloods and landslides. Western Visayas and Bicol Region will have cloudy skies with light to moderate rainshowers and thunderstorms,” Pagasa said in its daily bulletin.

Metro Manila and the rest of the country will be partly cloudy to cloudy with isolated rainshowers or thunderstorms, it added.

Moderate to strong winds blowing from the northeast will prevail over Luzon and western Visayas and the coastal waters along these areas will be moderate to rough. Elsewhere, winds will be light to moderate coming from the northeast with slight to moderate seas.