All classes in public and private schools were suspended in one province in the Bicol region southeast of Manila, where Tropical Storm Mitag was forecast to make landfall later this week.
Mitag, packing sustained winds of 85 kilometers (53 miles) per hour with gusts of up to 100 kph (63 mph), is approaching from the Philippine Sea , east of the country.
Chief government forecaster Nathaniel Cruz said it could became a "super typhoon" with winds of more than 220 kph (138 mph) when it makes landfall as early as Friday.
"It's still far, and that means we still have time to conduct preparedness," Cruz said. "With two days in the open sea, it has a big potential to become a very strong typhoon."
Recent rains have saturated the ground around Mayon volcano the in Bicol region, and Arroyo was worried there could be a repeat of last year's landslides and flashfloods that killed more than 1,000 people, said Anthony Golez, deputy director of the Office of Civil Defense.
Gov. Joey Salceda of Albay province, where last year's typhoon unleashed tons of volcanic debris that wiped out entire villages, said schools may be used as temporary shelters.
The same communities devastated last year were again flooded by rains from an earlier storm and one wooden bridge connecting two villages in Daraga township was washed away, local officials said.
In neighboring Sorsogon province, radio announcements advised officials, community leaders and the public to prepare to evacuate, provincial disaster officer Noel Pura said.
Golez said Arroyo issued the evacuation order from Singapore , where she was attending a summit of Asian leaders.
"All these are precautionary measures of the president because she hates to see when she returns any untoward incident because of the typhoon," he said.