Typhoon Rammasun has made landfall in the Philippines with wind gusts of up to 185 kilometres per hour.
Weather authorities say the typhoon, known locally as Glenda, has strengthened as it approaches the province of Quezon in the central Philippines.
The typhoon is travelling west-northwest at 19km/h.
It's expected to pass over the capital Manila before midday today then move away from land in the evening.
The Philippine Atmospheric, Geophysical and Astronomical Services Administration (PAGAS) has issued heavy rainfall warnings and says flooding in low lying areas and landslides in mountainous areas are possible.
Authorities say strong winds may cause extensive devastation to agriculture, damage houses and cut electricity.
They're also warning against travel by land, sea or air in some areas.
Rammasun is expected to hit fishing communities in the eastern Philippines and then bring heavy rain to Manila and other heavily populated northern areas, civil defence officials said
Secretary General Gwendolyn Pang has told Radio Australia the Red Cross is preparing for the impact of the typhoon and its after-effects.
"In the past, as we have observed, even with slight rain we have flooding in central Manila," he said.
"So this one, if it's brought by a typhoon, we're expecting heavy flooding, because with slight rain we are experiencing flooding already."
Philippines on alert
The central Philippines province of Leyte, which was devastated by Typhoon Haiyan late last year with more than seven thousand people killed or missing, has been placed under a storm alert.
Several tents of Haiyan survivors have been damaged by rains from Typhoon Rammasun.
Food and other items have been readied by government agencies.
Schools were closed on Tuesday, and thousands of passengers have been stranded as sea travel, and several domestic and international flights have been cancelled in the northern and eastern regions.
The Philippines is hit by about 20 major storms a year, many of them deadly, and Rammasun is the first to make landfall since the rainy season began last month.
Authorities said they were taking every precaution to avoid fatalities, after Super Typhoon Haiyan left about 7,300 people dead or missing when it tore across the central Philippines in November last year.
"We are already warning the public to be on alert for possible effects of the weather disturbance: landslides, flash floods, strong rains and winds," head of the National Disaster Risk Reduction and Management Council, Alexander Pama, said.
© ABC 2014
05:56 EDT Dr Rob Gordon has worked with survivors of fires, floods, earthquakes and droughts; he's seen more devastation in his career than you'd care to imagine.