Brace for a wet Christmas season due to the potential impact of the La Niña phenomenon, the Philippine Atmospherical, Geophysical and Astronomical Services Administration (PAGASA) said Monday.
In an interview over ABS-CBN’s Teleradyo, Analiza Solis, Climate Monitoring and Prediction Section chief, said the La Niña episode will reach its peak in November to December.
“This could possibly last until April next year,” she added.
Meanwhile, tropical depression “Nika” was estimated at 340 kilometers west of Sinait, Ilocos Sur with maximum sustained winds of 55 km/hr near the center and gustiness of up to 70 km/h while maintaining its strength.
It was forecast to exit the Philippine area of responsibility on Monday and to make landfall over Hainan province, Southern China on Wednesday.
The weather bureau earlier announced the onset of La Niña would persist until early 2021, saying there could be a 75 percent chance for it to become full blown characterized by above-normal rainfall conditions and increased tropical cyclone activity from October to the first quarter of 2021.
“La Niña started in October. We have a weak to moderate (one) now. It is possible to become moderate to strong up to the first quarter,” Solis said.
The combined effect of the simultaneous occurrence of a tropical depression, an inter-tropical convergence zone, a low pressure area and the southwest monsoon could trigger an extreme rainfall event in Luzon, especially in its eastern portion, the Visayas and Mindanao, she warned.
Too much rainfall could fill dams in Luzon, especially the Angat Dam (in Bulacan), she said.
“We have to maximize the potential benefits of La Niña. We only have to avoid its adverse impacts of floods and landslides,” she added.
According to Solis, “historically, there are instances of a back-to-back La Niña. It does not necessarily mean we will be having that but there is such a thing.”
The National Water Resources Board recently reduced the 46 cubic meters per second water allocation for Metro Manila due to a low water elevation at Angat Dam.