Southwesterly Winds Indicate Rainy Season Arrival
The onset of the rainy season could be imminent as southwesterly winds are expected to dominate western Luzon this weekend. According to local weather experts, this wind pattern often signals the beginning of the southwest monsoon or “habagat.” The southwesterly winds will likely bring scattered rain showers and thunderstorms to several areas including Palawan, Occidental Mindoro, Metro Manila, Cavite, Batangas, Zambales, Bataan, Pangasinan, La Union, Ilocos Sur, and Ilocos Norte starting Friday, May 30.
“The southwesterly winds will become the dominant wind pattern over western portions of Luzon by this weekend,” a weather specialist shared. “This shift will increase the chances of scattered rain showers, especially in the afternoons and evenings, over these areas.”
Criteria for Declaring the Rainy Season
Authorities monitor rainfall closely and declare the start of the rainy season when at least seven out of thirteen key stations record 25 millimeters of rain over five consecutive days. This must be accompanied by a prevailing shift of winds to the southwest. This year, the southwesterly wind flow is expected to meet these conditions soon, signaling the beginning of the rainy season.
Additional Weather Systems Affecting Luzon
Meanwhile, a frontal system—the boundary between warm and cold air masses—is forecasted to continue bringing scattered rain and thunderstorms over extreme Northern Luzon from Wednesday, May 28, to Saturday, May 31. This will add to the wet weather conditions in the region.
Weather Trends in Other Regions
In contrast, rainfall will likely decrease in Palawan, Visayas, and Mindanao due to the weakening of the Intertropical Convergence Zone (ITCZ) and the dominance of easterly winds on Wednesday and Thursday. “While some brief afternoon or evening rains may still occur, the weather will generally improve in these regions during this period,” experts noted.
For the rest of the country, easterly winds will prevail, bringing warm weather with occasional brief rain showers and thunderstorms over the weekend.
For more news and updates on the rainy season, visit Filipinokami.com.
