Vietnam is hunkering down in preparation for a weakened Typhoon Nesat, evacuating nearly 20,000 people from coastal areas.

The hard-hit Philippines is bracing for yet another monster storm building off its coast in a region that's already waterlogged from monsoon flooding.

Vietnam's national weather forecasting centre says Nesat has been downgraded to a tropical storm. It is now packing sustained winds of up to 117 km/h and is expected to make landfall Friday afternoon.  Heavy rains are being reported in northern and central areas, and warnings have been issued for flash floods in low-lying areas and for landslides in mountainous regions.

High winds are whipping through the capital of Hanoi's as the powerful storm churns off the northern coast.

In the Philippines, more than 160,000 people were still in evacuation centers Friday, three days after Nesat tore a path across the country's main island and triggered some of the worst flooding in the capital in decades.

Even as the weather improved with some sunshine, more misery hit residents of Bulacan province just north of Manila when three dams released excess water, flooding farmland and sending residents in towns downstream wading through neck-deep waters.

Bulacan Gov. Willy Alvarado said he called dam administrators to temporarily stop the release of water, which he said unleashed flooding on "unprecedented" levels.   

Army and police rescuers distributed food and other relief goods to those stranded on rooftops in Calumpit and Hagonoy townships in Bulacan.