The flood alerts
Under the heavy rainfall warning system, a yellow rainfall advisory is raised when the expected rainfall amount is between 7.5 mm and 15 mm within one hour and likely to continue.
Communities given this advisory are advised to be aware of the weather condition and warned that flooding may be possible in low-lying areas.
The orange rainfall advisory is raised in areas where rainfall is between 15 mm and 30 mm within one hour. Flooding is a definite threat in communities under the orange alert.
A red rainfall advisory is issued when downpours constitute an emergency. This is raised when observed rainfall is more than 30 mm within one hour or if rainfall has continued for the past three hours and is more than 65 mm.
When PAGASA raises a Red warning, communities should be prepared to respond. It means serious flooding is seen and that residents should be ready to evacuate to safety.
How it works:
Based on the advisory level, find out if your area is affected. For example, if you live in Marikina, go to Project Noah. The real-time flood reference for Marikina can be seen if you click flood maps and go to flood inundation. PAGASA generates flood scenario for Marikina river every 10 min.