PAGASA: El Niño in decaying stage

The current El Niño continues to weaken in the tropical Pacific. Majority of climate models suggest that El Niño is in its decaying stage, returning to ENSO-neutral condition by mid-2016.

(*ENSO-neutral refers to when neither El Niño nor La Niña is present. These periods often coincide with the transition between El Niño and La Niña events.)

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[Read: Updates on El Niño]

Meanwhile, the possibility of a developing La Niña is favored during the second half of 2016. With this current state, La Niña Watch is now in effect. A La Niña event is characterized by a persistent cooler than average sea surface temperature anomalies (below -0.5 °C) over the tropical Pacific.

Rainfall assessment for the month of April showed that most parts of the country received way below to below normal rainfall except for the provinces of Compostela Valley, Agusan del Sur, North Cotabato, Pangasinan, Cavite, Rizal, and Metro Manila where above normal to near normal rainfall were observed. Further analysis showed that 23 provinces were affected by dry spell while 28 provinces, mostly from Mindanao, experienced drought conditions in April.

Coming out of summer

Most parts of the country experienced warmer than average air temperatures due to the prevalence of ridge of high pressure area. The highest daytime temperature in the country was recorded at 40.1°C (Apr. 27) in Isabela State University-Echague. Two warmest daytime temperatures that surpassed their historical extremes were also observed: Malaybalay (36.4°C on Apr. 15, 2016 topped 36.2°C on April 24, 1998) and General Santos (39.4°C on Apr. 16, 2016 beat 39.0°C on April 5, 1988).

The month of May marks the weakening of the easterlies and gradual start of southwest windflow. Other weather systems that are likely to affect the country for May are the Intertropical Convergence Zone, easterlies, low pressure areas, ridge of high pressure areas, and zero or one tropical cyclone to enter the Philippine Area of Responsibility. Afternoon or early evening thunderstorm activities are also expected to increase during the period.

Below to way below normal rainfall conditions are expected over Luzon and Visayas while significant portions of Mindanao are predicted to have near normal to above normal rainfall conditions. Drought and dry spell outlook for the month show that 23 provinces will likely experience drought and 37 provinces may experience dry spell. For a complete list of these provinces, please refer to the Drought/Dry Spell Outlook map.

May predictions

Generally warmer than average air temperatures are expected in many parts of the country. Predicted ranges of temperature in May are as follows: mountainous Luzon (15.0-29.9°C), lowland Luzon (18.2-42.3°C), lowland Visayas (19.5-39.6°C), mountainous Mindanao (16.1-36.0°C), and lowland Mindanao (19.1-39.0°C).

PAGASA will continue to closely monitor the on-going El Niño and developing La Niña and updates shall be issued as appropriate. Meanwhile, concerned agencies are advised to take precautionary actions and intervention measures to mitigate the adverse impacts of El Niño.

—From the Philippine Atmospheric Geophysical and Astronomical Services Administration

*For further information, please contact the Climatology and Agrometeorology Division at telephone numbers 434-0955 or 435-1675.