THE system of tropical weather warnings used by Pagasa and the National Disaster Risk Reduction and Management Council (NDRRMC) to advise the public of potential or imminent hazards is, I think, about as clear as they can make it. 'Storm signals' numbered 1 to 5 describe wind hazards in terms of severity and estimated time of arrival. The color-coded rainfall warnings — red, orange and yellow — do the same for rain and flood hazards, albeit with much less lead time — about two hours — whereas storm signals can be issued about a day ahead.

These warnings are only useful, however, if they are issued in a timely manner. In the case of the flood calamity that struck Metro Manila and nearby provinces on Wednesday, the first warnings were not received until the disaster was already well underway.