EXPLAINER: PAGASA's 'Rainfall Warnings'

As the relentless rain caused by the Carina-enhanced Habagat submerged Metro Manila in floods on Wednesday, the state weather bureau PAGASA continues to issue color-coded "rainfall warnings."

PAGASA has used this system since 2012  to help communities prepare for possible disasters. 

The rainfall warning system is classified into 3 levels: Yellow, Orange, and Red. 

Red Rainfall Warning ASSOCIATED HAZARD: Serious FLOODING in flood-prone areas

• This is the highest warning and areas under this warning are seeing 30 mm or more rainfall in an hour, which is expected to continue in the next two hours.
• If an areas is under a Red Rainfall Warning, residents are warned of a possible "serious flooding," particularly in low-lying areas. 
• Residents in areas that have low elevation, such as coastal towns and cities are advised to evacuate immediately. 

Orange Rainfall Warning ASSOCIATED HAZARD: FLOODING is still THREATENING

• Areas under the orange warning see intense rainfall of 15 to 30 mm in an hour, which is expected to continue for the next two hours. 
• At this point, there is a threat of flood in low-lying areas and near rivers. 
• The public must remain alert and prepare for eventual evacuation.

Yellow Warning -ASSOCIATED HAZARD: FLOODING in flood-prone areas.

• This means around heavy rainfall of 7.5 to 15 mm in an hour, which is seen to continue for the next two hours. 
• Flood is possible in low-lying areas and near rivers. 
• Residents are advised to monitor the news for further updates. 

On Wednesday, PAGASA issued another red rainfall warning over Metro Manila and nearby provinces due to expected heavy rains. 

Red Rainfall Warning (as of 5 p.m.) 

• Metro Manila
• Rizal
• Bataan
• Zambales
• Bulacan
• Pampanga

Orange Warning Level

• Tarlac province

Yellow Warning Level

• Cavite
• Batangas
• Laguna
• Nueva Ecija
• Quezon(General Nakar, Real, Infanta, Mauban, Sampaloc)

PAGASA also said that light to moderate with occasional heavy rains are still expected over parts of Quezon within the next three hours. 

Tropical cyclone Carina has become even stronger and is now a Super Typhoon.

The National Capital Region was also placed under a state of calamity in due to massive flooding. —VAL, GMA Integrated News