PAG-ASA OFFICIALLY DECLARES FRIDAY AS ONSET OF RAINY SEASON

The Philippine Atmospheric Geophysical and Astronomical Services Administration (PAG-ASA) officially declared Friday as the start of the rainy season for this year. 

Below is the press release from pagasa.dost.gov.ph.

ONSET OF THE RAIN ASSOCIATED WITH THE SOUTHWEST (SW) MONSOON SEASON 

May 27, 2011

For the past few days, climatological manifestations of the start of the southwest monsoon season have been observed. These include the appearance of the heat lows or convective activities dominating most of the Asian continent, an elongated area of low pressure (monsoon trough) with its axis extending towards south China sea and northern Philippines, early morning and late afternoon rainshowers and thunderstorms and the progression of southwesterly windflow over western Visayas and Luzon as generated by the cross equatorial wind. Occurrence of Tropical Storm "Chedeng", upgraded to typhoon intensity enhanced the southwesterly windflow as it moves north towards southern Japan. This eventually triggered the total setting-in of the Southwest (SW) monsoon season with its associated rains over the western section of the country. These developments initiated the onset of the rainy season in the country associated with the SW monsoon "HABAGAT".

The southwest monsoon is associated with the occurrence of an intermittent to continuous rains in Metro Manila and the western sections of Luzon and Visayas. However, it is anticipated that some breaks in the rain events (called monsoon breaks) will occasionally occur as the North Pacific high pressure ridge strengthens. This situation usually occurs before the peak of the rainy season during the month of July. The rainy season will start receding towards the end of September.

The PAGASA/DOST will continue to monitor and inform the public of any significant weather changes. For more information, please contact Weather Branch PAGASA at telephone numbers 927-1541/929-4570/922-1996 and 926-4258.