12 August 2012

A double-shot for the Philippines

Total event rainfall in the northern Philippines based on the
NASA TRMM Multi-sensor Precipitation Analysis (MPA).
One of the major stories in international news this past week was the end of eleven (yes, 11) straight days and nights of torrential rains in metropolitan and suburban Manila on the northern Philippine island of Luzon. The island, especially its southwestern portions, was stuck in the midst of a rare combination of tropical cyclones and monsoon rains at two different times. The results have been devastating for the area of 12 million people around Manila as well as vast farming areas to the north of the metropolitan region. The city received as much as 700 mm (27.5 inches) of rain according to satellite-based precipitation analyses released by the NASA Precipitation Measurement Missions project and the NASA Earth Observatory.

NASA Terra image of typhoon Saola in the
vicinity of the Philippines on 30 July 2012.
Typhoon Saola (known as "Gener" in the Philippines) whipped up in the western Pacific Ocean around the last week of July and passed just northeast of Luzon around 30 July on its way to Taiwan and the coast of China, where it made landfall on 1 August. The NASA Terra satellite captured the picture at left around the time of Saola's closest approach to Luzon on 30 July, though by that time the storm had already caused damage and power outages in the northern islands of the Philippines. The BBC provided a video report on conditions in Manila soon after the storm passed. At least 37 fatalities in the Philippines were attributed to this storm and its effects. In particular, the monsoon season had already begun in the northern portion of the South China Sea, and Saola's position and strong storm circulation at the edge of that region served to enhance the southwesterly monsoon flow across the Philippine islands. The direction of this flow led to its interaction with the Sierra Madre and other mountain ranges that run north-south through the northern islands, especially those around the Manila metropolitan region. The low-level flow off of the warm ocean, directed upslope across the city and enhanced in strength by the typhoon circulation, led to massive rainfall amounts and extensive flooding in the area. At least 40,000 people on Luzon were affected by Saola and its interaction with the monsoon system.

Flooding following typhoon Haikui in Rodriguez town, an eastern suburb
of metropolitan Manila. The overflowing Marikina River is visible in the
background. Photo provided by the Department of National Defense
and republished by Reuters and The Atlantic.
As if that wasn't enough, typhoon Haikui began in the western Pacific Ocean around 1 August and also moved westward, eventually making landfall in China as well. Although Haikui remained farther east and north of the Philippines than Saola, the monsoon winds were already in place and strengthened by that time, and Haikui's storm circulation again served to enhance the southwesterly flow across Luzon and the northern Philippine islands. The storm was devastating for the metropolitan region and nearby farming areas, resulting in widespread flooding of Manila, its suburbs, and the river valleys surrounding Manila Bay and Laguna de Bay.
Flooding following typhoon Haikui in Bulacan, a suburban and agricultural
province to the north of metropolitan Manila. Photo provided by the
Department of National Defense and republished by
AFP/Getty and The UK Telegraph.

The Philippine Department of National Defense provided aerial photographs of flood impacts that were reprinted by Reuters in The Atlantic (example at right) and AFP/Getty in The UK Telegraph (example at left).

This is considered the worst flooding event since tropical storm Ketsana in 2009, which led to 464 fatalities. At least 85 fatalities have been reported for this event thus far, and at some point flooding conditions covered 80% of metro Manila with at least 250,000 city residents displaced and at least 3 million affected overall. Blame regarding flood and disaster preparation continues to fly between the Philippine Atmospheric Geophysical and Astronomical Services Administration (PAGASA), which had already been working on hazard maps for Luzon and Manila, and the National Disaster Risk and Reduction Management Council (NDRRMC). In the meantime, clean-up and relief efforts have begun, even as the full scope of the disaster and the total damages from the combination of these two storm and flooding events are still being tallied.

NASA Terra image of tropical storm Helen/Kai-Tak
in the vicinity of the Philippines on 13 August 2012.
Updated 16 August 2012

Make that a "triple-shot" for the Philippines. Adding insult to injury, tropical storm Helen/Kai-Tak crossed the northern island of Luzon this week, bringing yet more rain to still-flooded and recovering urban and agricultural areas. This latest storm made landfall on Luzon and led to at least seven more fatalities in the Philippines. A brief video report from Reuters is also available regarding this latest storm event.

A number of local and international organizations are involved in disaster recovery efforts, including the Philippine Red Cross.

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