I. Situation Overview
On 27 July 2021 at 11 AM, DOST-PAGASA forecasted that the Southwest Monsoon would bring moderate to heavy with at times intense rains over Ilocos Region, Zambales, and Bataan. Meanwhile, light to moderate with at times heavy rains would prevail over Metro Manila, CALABARZON, Abra, Benguet, Tarlac, Pampanga, Bulacan, and Occidental Mindoro. Moreover, occasional gusty winds would be experienced over these areas especially in the coastal and upland localities. Under these conditions, scattered to widespread flooding and rain-induced landslides were possible during heavy or prolonged rainfall especially in areas that are highly or very highly susceptible to these hazards as identified in hazard maps.
On 31 July 2021 at 11 AM, the effect of the Southwest Monsoon has weakened. It was forecasted to bring cloudy skies with scattered rainshowers and thunderstorms over Ilocos Region, Benguet, Zambales, and Bataan.
Source: DOST-PAGASA Weather Advisory
II. Status of Affected Areas and Population
A total of 300,894 families or 1,164,004 persons were affected by the Southwest Monsoon in 1,057 Barangays in Regions NCR, I, III, MIMAROPA, VI and CAR (see Table 1).