JULY – DECEMBER 2016
The 2015-2016 strong El Niño event had ended in June. Both oceanic and atmospheric indicators have returned to neutral values which suggest that El Niño Southern Oscillation (ENSO)-neutral condition is now present in the tropical Pacific.
Meanwhile, a La Niña is favored to develop by August-September-October 2016 season, as the central and eastern equatorial Pacific (CEEP) continue to exhibit cooler than average sea surface temperatures (SSTs). A La Niña is characterized by a persistent cooler than -0.5°C sea surface temperature anomalies (SSTAs) over the CEEP.
July to September 2016
The season favors a shift from ENSO-neutral to La Nina conditions as predicted by the majority of climate models.
The period is the peak of the Southwest (SW) monsoon season or “Habagat” and tropical cyclone activity is likewise at its maximum. Rain-causing weather systems such as thunderstorms, inter-tropical convergence zone (ITCZ), low pressure areas (LPAs), tropical cyclones and enhanced SW monsoon will dominate the season bringing widespread and heavy rainfall in many places of the country. Five (5) to eleven (11) tropical cyclones are likely to develop/enter the Philippine Area of Responsibility (PAR). Most tropical cyclones generally move in westward and northwestward directions. Monsoon breaks are likely to occur during the period.
Average rainfall condition are predicted to be above normal in most parts of northern and central Luzon and some areas in Visayas and Mindanao while near normal for the rest of the country. Gradual recession of rains, associated with the SW monsoon, is expected during the latter part of September up to early October.
October to December 2016
A weak La Nina will be likely during the season with around 55-60% chance that it will continue until Dec-Jan-Feb 2016-2017 season.
The period covers the first half of the Northeast (NE) monsoon. Weather systems likely to influence the country are the tail end of the cold front, ITCZ, easterly wave, ridge of high pressure area (HPA), the easterlies and four (4) to nine (9) tropical cyclone occurrences. Tropical cyclones originating from northwestern Pacific Ocean tend to move in a westerly direction during the season; their most likely tracks are expected between Visayas and Central Luzon with secondary tracks over Northern Mindanao.
For October-November-December season, generally the entire Philippines will likely receive above normal rainfall except for some patches of near normal rainfall condition. Due to this surplus in rainfall, several areas in the country are expected to experience prolonged wet conditions that may cause floodings and rain-induced landslides.
Slightly warmer than average temperatures are likely to be felt during the season, however, cold surges may still be experienced especially during the latter part of December.
PAGASA will continue to closely monitor these climate conditions and regular updates and advisories shall be issued as appropriate. Concerned agencies are advised to take precautionary measures to mitigate the potential adverse impacts of this phenomenon. For further information, please contact the Climatology and Agrometeorology Division (CAD) at telephone numbers 434-0955 or 435-1675.
VICENTE B. MALANO, Ph.D.