Philippine Area of Responsibility
From WikiPilipinas: The Hip 'n Free Philippine Encyclopedia
The Philippine Atmospheric, Geophysical and Astronomical Services Administration, PAGASA, is a Philippine national institution dedicated to provide flood]and typhoon warnings, public weather forecasts and advisories, meteorological, astronomical, climatological, and other specialized information and services primarily for the protection of life and property and in support of economic, productivity and sustainable development.
PAGASA monitors tropical cyclone activity and issues warnings within its area of responsibility. This area is bound by an imaginary line drawn along the following coordinates:
- 25°N 120°E, 25°N 135°E, 5°N 135°E, 5°N 115°E, 15°N 115°E, 21°N 120°E and back to the beginning. 
Tropical cyclone bulletins are issued by PAGASA every six or twelve hours for all tropical cyclones within this area.