Havoc in typhoon Ketsana’s wake

High-tension 500KV power poles are pictured in a flooded area near Hue in southern Vietnam [AFP]

Typhoon Ketsana is now bringing heavy rain into central and northern Vietnam and this will be the main focus for widespread flooding over the next few days.

Further east, the Philippines is still struggling to recover from what has now been described as the worst flooding since 1967.

Bear in mind that Manila, the capital, usually averages 2085mm of rain each year.

So this is an extremely wet part of the world which usually sees over 20 tropical storms in a typical year.

However, some parts of Luzon, an island in the northern Philippines, suffered non-stop heavy rain for three consecutive days with as much as 455mm falling in parts of Luzon in that time.

That amount of rainfall in such a small space of time is always going to cause problems even in one of the wettest parts of the world. To put it into perspective, London, which is seen by many as a rather wet place averages 593mm in a typical year.

Vietnam flooding

Philippines floods

Number of dead: 240  Number rescued: 12,000  Number in emergency shelter: 450,000  Number affected in Manila: 1.9 million Total assets owned by National Disaster Coordination Council:  Ambulances: 12  Rubber boats: 59  Cargo trucks: 33  In addition, the US military has donated 1 helicopter and 5 rubber boats

In the case of the Philippines, not only have we had a very wet rainy season coupled with the slow passage of Ketsana – which threw down copious amounts of rain over a short period of time as the storm crossed Luzon (over a month’s worth in less than a day), but the outflow from the storm has continued to feed showers across the same areas even after the storm had passed.

Ketsana then re-intensified as it moved into the warm, moist waters of the South China Sea and is now bringing widespread floods into Vietnam.

Da-Nang, along the southern and eastern coast, has already seen 285mm of rain in just 24 hours and the city of Hue, farther inland, has seen 336mm over the same time-frame.

And there is more to come.

Ketsana will now quickly weaken as it makes its way over land but further flooding and mudslides are expected.

Heading toward China

At the same time, the circulation from the storm is set to pump moisture across the south coast of China where a weather front linking back to the storm will extend torrential downpours along the coastal fringes of southern China during the next few days.

The same system stretches through Hong Kong into Taiwan and beyond.

Drier weather is expected in southern China and Vietnam by the end of the week but by that stage tropical storm Parma, the 19th storm of the season will be making its presence felt across the Philippines.

The storm looks set to become a typhoon some time on Friday with winds expected to reach up to 120km/h with gusts of around 145km/h.

The only consolation that I can offer is that it does look unlikely to make a direct hit on the country.

It should pass to the east of Luzon and remain offshore but the outer bands of the storm system are likely to feed further heavy rain across much of the country.