|Courtesy of NASA-JAXA TRMM|
This was the assessment made by a joint US-Japanese scientific project that also measured the amount of rainfall dumped by the tropical storm in the Visayas and Mindanao.
The Tropical Rainfall Measuring Mission or simply TRMM, a joint project between the US National Aeronautics Space Administration (NASA) and the Japan Aerospace Exploration Agency (JAXA), said Sendong dumped as much as more than 400 millimeters of rainwater over Mindanao's northwest coast.
"It was here in places like Cagayan de Oro City and Iligan City that the most devastating mudslides occurred," the TRRM report said.
It added that most of the heavy rain was reported to have fallen over the mountains before flowing down in raging rivers.
In comparison to Sendong, storm Ondoy, the storm that also caused massive floods in the Philippines back in 2009, dumped around 459mm of rainfall in Metro Manila when it hit the metropolis, according to measurements taken by state weather bureau PAGASA (Philippine Atmospheric, Geophysical and Astronomical Services Administration).
PAGASA gets flak
PAGASA has received flak for its alleged failure to give proper warnings to communities in Sendong's track, including an allegation made by weather bloggers that the weather bureau announced to the public that a storm was headed in less than 24 hours before its forecast landfall.
The National Disaster Risk Reduction and Management Council's (NDRRMC) first public advisory on Sendong, which was issued 11 a.m. on December 15, also showed a PAGASA tracking map stating that the storm won't hit Iligan City and Cagayan de Oro.
The next NDRRMC severe weather bulletin issued 5 p.m. of the same day showed a revised PAGASA tracking map, with the two cities on the storm's path.
PAGASA also raised storm warnings the same afternoon.
The storm made landfall mid-afternoon the following day, then struck Malaybalay before devastating Cagayan de Oro and Iligan in the middle of the night.
The resulting flashflood has killed 976 people, as of latest NDRRMC count on Wednesday morning. Dozens remain missing, while damage to properties is approaching P1 billion.
The Palace and the NDRRMC have cleared PAGASA of any fault, saying the agency gave warnings even days before the storm stuck.
Presidential Communications Development and Strategic Planning Undersecretary Manuel L. Quezon III showed the media copies of SMS advisories on the storm that PAGASA sent to Malacañang.
"We have been getting updates since December 14 via text," he said.
One SMS sent to the Palace on 12:46 p.m. of December 14 by senior PAGASA official Robert Sawi said: "The tropical depression over the Pacific is estimated at 1,480 km E of Mindanao with maximum winds of 55 kph. It is moving west at 19 kph and is expected to enter PAR by tomorrow morning. It will start affecting Visayas and Mindanao on Friday. This may trigger floods and landslides. Please take all the necessary precautionary measures. FYI. TY."
The SMS advisories, however, did not contain information on the storm's rainfall amount.
PAGASA continued to relay to the Palace its updates on the storm.
Quezon said the same weather alerts were sent to the NDRRMC, the Philippine Information Agency, and the Radyo ng Bayan (National Radio).
"As I was told in Butuan, many PIA regional offices work with Radyo ng Bayan to send alerts and do SMS alerts too," he said.
Quezon said the Palace is preparing a comprehensive timeline on the disaster.