State weather forecasters issued Monday afternoon a green rain warning signal over Metro Manila, indicating possible intense rain in the next three hours.

 

The Philippine Atmospheric Geophysical and Astronomical Services Administration estimated the rainfall may be heavy to intense, from 7.5 to 25 mm per hour.

 

"Heavy to intense (rainfall of 7.5 to 25.0 mm per hr) was observed over Manila for the past hour and most likely to continue for the next three hours," it said in its 5 p.m. alert, which was posted on its Twitter account.

 

It said flooding may threaten low-lying areas and those located near the river channels.

 

"People are advised to closely MONITOR the weather condition and WATCH OUT for the next warning," PAGASA said.

 

Green alert is the second of a three-level alert system that means intense rain and flooding is threatening.

 

Yellow means "caution" as heavy rain is expected.

 

Red means more than 30mm of rain is expected and serious flooding may occur, and calls for evacuation.

 

Since Sunday night, heavy rain had caused flooding in parts of Metro Manila, prompting local officials to suspend classes for Monday.

 

PAGASA forecaster Manny Mendoza earlier said the heavy rain may continue on Tuesday, with relief from the heavy rain not due until at least Wednesday.

 

PAGASA also said the heavy rain was due to the southwest monsoon enhanced by a tropical storm heading for China. — RSJ, GMA News