The Philippine Atmospheric, Geophysical and Astronomical Services Administration (PAGASA) on Friday, March 22 said less rainfall and warmer temperatures may persist in some parts of the country until the third quarter due to the ongoing El Niño and pre-developing La Niña.

During a press conference, PAGASA-Climatology and Agrometeorology Division (CLIMPS) Officer-in-Charge Ana Liza Solis said although El Niño has already weakened and is expected to transition to an El Niño Southern Oscillation (ENSO)-neutral condition between April and June, its effects may persist until June or July because of a “lag effect.”

El Niño is currently causing significant reductions in rainfall and drier-than-usual conditions, which led to dry spells and droughts across the country.

Furthermore, the probability of a La Niña developing later this year has increased to 55 percent.

Historically, a pre-developing La Niña has a “reversal effect” on the rainy season, which may result in below-normal or 60 percent reduction in average rainfall in some areas between July and September, Solis explained.

‘Utilize resources intelligently’

During this period, warmer temperatures also contribute to faster moisture evaporation, which leads to faster depletion of water reservoirs.

Furthermore, if rainfall is low, dams are less likely to be replenished.

If the current condition persists, PAGASA is not ruling out the possibility that the water levels of major dams in Luzon may continue to decline.

PAGASA hydrologist Richard Orendain said the Angat Dam could potentially hit its 180-meter “low-water” mark by June if the current water allocation and basin rainfall will remain the same in the next three months.

He added that PAGASA projects that the Angat Dam will reach 182 meters by the end of May, which is still good given that its water level typically falls below 180 meters during this time.

Angat Dam is the major water source for Metro Manila.

However, PAGASA senior hydrologist Rosalie Pagulayan urged the public to “utilize our [water] resources intelligently,” although water concessionaires and other government agencies have put in place measures to ensure water availability and prevent a repeat of the water shortage in Metro Manila in 2010.

The State weather bureau said the start of the southwest monsoon or “habagat” season in June may help in the “gradual” increase in the water levels of some dams in Luzon.

Meanwhile, Angat Dam typically reaches its 212-meter normal high water level during the northeast monsoon or “amihan” season, from October to March.

To help conserve water, PAGASA advised the public to use a glass of water when brushing; take a bath in five minutes or less; use water basins when washing dishes by hand; water plants early in the morning or evening; use a bucket of water and a rag to wash cars or bikes; check for leaks in water pipes or toilets; do not flush the toilet just to dispose of small trash; only use the washing machine when it is fully loaded; and collect rainwater and use it for watering plants or washing your car.