The ongoing oceanic and atmospheric patterns in the equatorial Pacific reflect the continuation of a weak to moderate La Niña. The latest observations, combined with model forecasts, suggest that La Niña will be of weak-to-moderate strength this January-February, and will gradually weaken and expected to dissipate between March and May. Its peak is likely this January.
The weather systems that influenced the country’s climate during December were Northeast (NE) monsoon, ridge of High Pressure Area (HPA), tail end of the cold front, wind convergence, Low Pressure Area (LPA) and one tropical cyclone. TS “Sendong” (Dec15-18), ranked first for the top ten (10) 2011 Philippine destructive tropical cyclones with the most number of deaths totaling to 1,257 as reported by the National Disaster Risk Reduction and Management Council (DRRMC). The cities of Cagayan de Oro and Iligan in region X suffered the most. Affected areas were regions VI,VII, IX, X, XI,CARAGA, & ARMM.
Climate pattern during the month was influenced by the on-going La Niña event enhancing rainfall distribution in most areas in the country. For three (3) consecutive months from October to December, Region VIII or CARAGA Administrative Region had experienced above normal to near normal rainfall condition. While from Nov-Dec., above normal rainfall values were noted over eastern and central Luzon including most areas of southern Tagalog region. These were manifestations of the La Niña impact.
Generally warmer than normal surface air temperatures were observed in many areas of the country during December. Likewise, during January, slightly warmer than normal surface air temperatures are expected to affect the country. However, cold surge is expected over extreme northern Luzon. Predicted ranges of temperature for January will be 17°C to 33°C over the lowlands of Luzon, 11°C to 24°C over the mountainous areas of Luzon, 20°C to 31°C for Visayas, 22°C to 34°C over the lowlands of Mindanao and 17°C to 24°C over the mountainous areas of Mindanao
Weather systems that will likely affect the country in January are the NE monsoon, tail end of the cold front, LPA, and ridge of HPA. One tropical cyclone is likely to develop or enter the PAR during the month. Rainfall distribution in most areas of northern and central Luzon will likely be above normal including the western section of Mindanao. Flooding, flashfloods and landslides are likely to happen in some affected areas, particularly over Visayas and Mindanao. The rest of the country is expected to have near normal rainfall condition.
PAGASA will continue to monitor the day-to-day rainfall/weather conditions and the large-scale climatic patterns that will affect the country especially on the possible impacts of the weak La Niña condition. Meanwhile, the public is advised to take precautionary measures against the likely floods and rain-induced landslides in hazard prone areas. Updates shall be issued as necessary.
NATHANIEL T. SERVANDO, Ph. D. (original signed) Administrator