Tropical Cyclone Ketsana

Pre-Landfall 1 | Summary
Posting Date: September 29, 2009, 8:00:00 AM

Having inflicted significant disruption to Manila and the northern Philippines, tropical storm Ketsana strengthened to a Category 2 typhoon early September 28 local time after it entered the warm waters of the South China Sea. According to the Joint Typhoon Warning Center (JTWC), as of 11:00 am EDT today Ketsana was about 370 km (230 miles) east of Vietnam and moving west-northwestward at about 16.7 kph (10.4 mph). Its maximum sustained winds were 167 kilometers per hour (103 miles per hour) with gusts of 203 kph (127 mph). It is expected to make landfall within 36 hours. Ketsana, which is the name of a fragrant tree in Laos, currently is gaining energy from the near-30° Celsius (86° Fahrenheit) water over which it is passing. It is forecast to reach its maximum intensity with sustained winds of slightly more than 176 kph (109 mph) in the next 12 hours. That is just short of a Category 3 typhoon. Thereafter Ketsana is expected to begin to weaken and slow as it encounters a longwave trough coming out of Southeast Asia. As of Monday morning the official death toll in the Philippines was 140, and more deaths are expected. Ketsana dropped 41.1 centimeters (16.2 inches) of rain in just 12 hours, the heaviest one-day rainfall ever recorded in Manila. The previous record was 33.5 centimeters (13.2 inches) in 24 hours, set over 40 years ago. Three-quarters of the city experienced flooding, with pockets under several feet of water. In areas around the city heavy precipitation caused landslides. More than 400,000 people in Manila alone were affected and the Philippine government declared a “state of calamity” in metropolitan Manila and 25 storm-hit provinces, enabling local officials to use emergency funds for relief and rescue. Electricity in much of Manila was disrupted and most businesses were shut down. The Manila airport was closed for hours. Towns east of Manila were submerged and there have been reports of landslides in other parts of Luzon. The homes of about 500,000 people were inundated, about 115,000 of whom are now in evacuation shelters. While many new buildings in the Philippines are constructed of concrete and masonry materials in place of traditional indigenous building materials, poor construction practices and low quality materials have exacerbated building damage. As the flood waters have begun to recede, large parts of Manila have been left covered in mud and debris. Cars carried by the floods were piled up, sometimes on top of each other. On Monday the Philippines National Disaster Coordinating Council gave an estimate of about USD 30 million in damage to infrastructure and agriculture. At this time, the AIR tropical cyclone team does not expect insured losses will be significant, in large part because of low take-up rates in the region. The team is continuing to analyze the available meteorological information, however, and will issue an update should their findings warrant one. In Vietnam, heavy monsoon rains over the weekend already have caused flooding in three districts. Authorities have warned fishermen not to go to sea and have begun evacuation and relief efforts. The Vietnamese coastline is at low elevation, which means a storm surge could reach far inland and cause considerable damage. More significantly, heavy precipitation from Ketsana as it slows along the Vietnam coast could exacerbate already flooded areas. Ketsana is forecast to make landfall near the city of Danang, which has a population of about 750,000 people.

Pre-Landfall 1 | Downloads
Posting Date: September 29, 2009, 8:00:00 AM