Pagasa devises new weather alert system for Metro Manila

INQUIRER PHOTO / NIÑO JESUS ORBETA

MANILA, Philippines—Is it going to rain?  The weather bureau will now answer this question through a newly devised system of warnings based on color—”yellow alert”, “green alert” and “red alert”— that will be disseminated to the public via  SMS, Twitter, the Pagasa Web site, and faxed advisories and the mass media.

The Philippine Atmospheric, Geophysical, and Astronomical Services Administration unveiled the new Metro Manila warning system for rain and thunderstorms on Tuesday, saying it was the first of its kind in the country.

Pagasa said these new warnings for the general public should spur communities and local governments to prepare for landslides, flash floods and river spills that could lead to evacuation.

“Early warning information empowers people to take action when a disaster is about to happen,” Pagasa said.

Under Pagasa’s heavy rainfall warning system, yellow warning is raised when the expected rainfall is between 7.5  and 15 mm within one hour and is likely to continue.

This advisory urges communities to be aware of the weather condition and warns them that flooding is possible in low-lying areas.

The next warning is green alert. This will be hoisted over certain areas where the rainfall observation is between 15 and 30 mm within one hour. Pagasa said communities under green alert must be prepared for flooding.

Red alert will be issued when downpours constitute an emergency, Pagasa said. This is raised when observed rainfall is more than 30 mm within one hour or if there has been continuous rainfall for the past 3 hours that is more than 65 mm.

When Pagasa raises this warning, communities should be prepared to respond to it. It means serious flooding is seen and that residents should be ready to evacuate to safety.

Pagasa also established an information and alert system for thunderstorms, which results in localized rainshowers.

The alert system for thunderstorms, which produce  rain showers for short durations,  specifies the likelihood of the formation of this weather condition over a certain area.

It will be raised when thunderstorm formation is likely within the next 12 hours and when it is threatening a specific area within the next 2 hours.

Pagasa will also notify the public if a thunderstorm is less likely to develop over a region.

All these alert systems will be disseminated through SMS, Twitter, Pagasa website, and faxed advisories.