Tropical cyclone 'Megi' is expected to cause major disruptions to transport and logistics in the Philippines and Vietnam.

After landfall on the southern Philippine island of Catanduanes on Oct 18, Megi swept across Luzon island towards the northwest, bringing torrential rain, strong and widespread flooding.

By Monday morning, the storm had moved out into the sea and was located about 390km west of the northern part of Luzon, winds blowing at 80km per hour.

Forecasts show the storm is expected to intensify as it makes its way across the South China Sea, and is forecast make landfall in Vietnam on Oct 24.

The storm has left a trail of destruction in the Philippines, where more than 22,000 people been evacuated as of 6am on Oct 19, according to the National Disaster Risk Reduction and Management Council.

Slips and flooding have damaged in transport routes, and port operations are also expected to face delays due to the severe weather conditions.