THE LA Niña phenomenon's possible re-emergence this year may elevate the risk for flooding and rain-induced landslides, particularly in the country's eastern seaboard.
Various weather systems, including the northeast monsoon or "amihan" that prevails annually during the year's latter part, could bring rains that might trigger such hazards in the area and other parts of the country, Philippine Atmospheric, Geophysical and Astronomical Services Administration (PAGASA) hydrologist Richard Orendain said Thursday.
"(The) onslaught of La Niña is an additional trigger for elevating the flooding and landslide risk," he said.
PAGASA said La Niña is the cool phase of the El Niño Southern Oscillation, a naturally occurring phenomenon of the climate system.
In its latest assessment this month, PAGASA said there's a 70 percent to 80 percent chance for La Niña's formation during the last quarter of 2021.
The risk for flooding and risk-induced landslides is higher in the country's eastern seaboard as this is where the "amihan" from the northeast and winds from the east generally "meet" and bring considerable rainfall, Orendain said.
He added that the eastern seaboard directly faces the Pacific Ocean where tropical cyclones (TCs) that may affect the country usually originate.
PAGASA said monsoon activity and winds from the east are stronger during La Niña.
The development of more TCs and occurrence of above-normal rainfall due to increased cloud formation are among La Niña's effects on Philippine climate, it said.
According to the weather bureau, most parts of the country may generally experience near-normal to above-normal rainfall from October to December this year.
The probability of above-normal rainfall is even high, it noted.
PAGASA forecast above-normal rainfall in 49 provinces this October, 51 provinces in November, and 25 provinces in December.
La Niña may persist until the first quarter of 2022, PAGASA's assessment showed further.
Next year, above-normal rainfall is possible over 48 provinces in January, 56 provinces in February, and 46 provinces in March, PAGASA said.
Among the provinces where above-normal rainfall may occur from October 2021 to March 2022 are those along the eastern seaboard. ( Catherine Teves)
