It’s official. Summer is over and the rainy days are here again. Weather bureau Philippine Atmospheric, Geophysical and Astronomical Services Administration (PAGASA) has announced the onset of the rainy season.
PAGASA earlier said that the rainy season will likely commence “sometime between late May and mid-June but the agency officially declared the start of the rainy season on Tuesday, May 24.
Based on PAGASA’s criteria, indicators of the onset of the rainy season include the prevalence of the southwest monsoon and rainfall of 25 millimeters in at least five out of eight PAGASA stations for five consecutive days.
In a press conference, PAGASA Assistant Weather Services Chief Anthony Lucero said most stations belonging to Climate Type 1 areas, facing the West Philippine Sea and being directly affected by the southwest monsoon or “hanging habagat” have recorded consecutive days with rainfall.
The weather stations in Type 1 climate areas are located in Laoag, Ilocos Norte; Vigan, Ilocos Norte; Dagupan, Pangasinan; Iba, Zambales; Occidental Mindoro; Metro Manila; Ambulong, Batangas; and Iloilo.
Lucero said there is a deep convection bringing heavy rains over the West Philippine Sea which is a clear manifestation that rains associated with the southwest monsoon have already arrived. The PAGASA official also noted that the wind direction has now shifted from east to southwest.
However, PAGASA clarified that the country is still under El Niño episode. “We can still expect dry spell in some areas until the end of July,” said Lucero. El Niño, which started in late 2015, is already in its decaying stage but may have lingering effects that could last until August.
Since last week, rains, winds and thunderstorms were felt in Metro Manila and nearby areas such occurrences usually lasted about one to two hours.
La Nina episode to follow
After El Nino, La Niña conditions or above normal rainfall will prevail, according to PAGASA. During or by the end of August, La Niña is expected to gradually develop but its actual impact will be felt towards the end of the year,” according to PAGASA.
La Niña episode may likely occur during the periods of November-January or December-February. “We expect more rains on the eastern side of the country, which are areas more vulnerable to La Niña,” Lucero said in a report.
These areas are Isabela, Quirino, Quezon, Albay, Camarines Norte, Camarines Sur, Catanduanes, Sorsogon, Masbate, Samar, Leyte, Surigao del Sur, Surigao del Norte, Agusan del Norte, Agusan del Sur, Davao Oriental, and Compostela Valley.
“Most of these provinces have their peak of rainy season during December and January. Because of the La Niña, it will enhance their rainy condition,” Lucero explained.