Revised Rainfall Warning Signal – PAGASA – August 9, 2012
The Philippine Atmospheric, Geophysical and Astronomical Services Administration (Pagasa) yesterday revised its rainfall warning signal (RWS) to avoid public confusion and better reflect the severity of the situation.
Pagasa changed the green alert to orange, which, according to the bureau’s administrator, Nathaniel Servando, is more appropriate for warning and disaster preparedness.
Pagasa spokesperson Venus Valdemoro denied speculations that the abrupt revision had been triggered by President Benigno Aquino’s repeated reference to orange instead of green alert in his meeting with the National Disaster Risk Reduction and Management Council (NDRRMC) on Wednesday.
Valdemoro told the Philippine Daily Inquirer that before the Wednesday meeting, Mr. Aquino had been informed of the modification from green to orange, and this explains the President’s reference to the new color.
Servando explained that green usually connotes tranquility, while orange evokes alertness.
“One of the reasons (for the change) is to harmonize the color-coding with that of rainfall intensity,” Servando said.
Under the color scheme, light blue indicates light rainfall, he said. Blue indicates moderate rainfall. Yellow means heavy rainfall, orange indicates intense rainfall, and red stands for torrential rainfall.
In a statement issued later, Servando explained: “The color orange was adopted as it is a more appropriate representation of the severity of the situation. This was based on suggestions after our information education campaign efforts with the media and discussions with the NDRRMC, the Metropolitan Manila Development Authority (MMDA) and the Department of the Interior and Local Government National Capital Region (DILG-NCR).”
Servando said the RWS remained open to suggestions for improvement. The system was launched on June 20 for Metro Manila, with the initial color codes yellow, green and red patterned after the coding system of the community-based flood early warning system under the United Nations Development Program (UNDP) project.
Under the revised RWS, yellow would stand for awareness; orange for preparedness; and red for emergency.
Valdemoro said most of the agency’s staff thought orange was more appropriate than green because orange was a mix of yellow and red and, thus, was in the middle. “From light to a heavy color,” she said.
She agreed that green tended to send the wrong message to people, who might not immediately realize the urgency of the situation based on the color, which basically connoted calmness.
But she reiterated that the warning system is a work in progress.
Right now what is important is the action the public would take if these warnings are raised, Valdemoro said.
Basically, she said, the revised RWS stands for three As: yellow means “advisory,” orange stands for “alert,” and red means “action.”
Pagasa raises the yellow warning when rainfall of 7.5 mm to 15 mm per hour is expected to fall and most likely will continue for the next three hours, which makes flooding possible in low-lying areas and areas near rivers.
The orange warning is hoisted when rainfall of more than 15 mm to 30 mm within an hour has fallen or is expected to fall and will most likely continue. It also indicates that continuous rainfall in the past three hours has been recorded to exceed 45 mm to 65 mm, thus, threatening floods.
The red warning is raised if the amount of rainfall has gone more than 30 mm within an hour or is expected to fall and will most likely continue. It also indicates continuous rainfall in the past three hours has been recorded to be more than 65 mm, calling for community response.
Under the red warning, serious flooding is expected and the public must take precautionary measures.