While El Niño is on a diminishing stage, the Philippine Atmospheric, Geophysical and Astronomical Services Administration (Pagasa) warned that the possibility of the country experiencing La Niña is rising.
According to the state weather bureau’s bulletin, the current El Niño continues to weaken in the tropical Pacific. It added that the country will have its neutral weather condition in the middle of the year or in June or July.
Acting Administrator Vicente Malano said the possibility of La Niña developing will occur during the second half of 2016. Malano added that with this development, the agency’s La Niña Watch is now in effect.
La Niña is described as an event characterized by a persistent cooler than average sea surface temperature anomalies or below negative 0.5 degree Celsius over the tropical Pacific.
La Niña conditions favor the formation of tropical cyclones over the western Pacific, thus increasing the number of typhoons. It is characterized by above normal rainfall and strong monsoon activity.
During a La Niña event, massive flooding due to days of intense rains brought by habagat or southwest monsoon will occur.
In 1997 to 1998, the country was hit by a strong El Niño which was followed by La Niña in 1999 when several parts of the country experienced intense rainfall and flooding.
About 58 people were killed in 1999 when pounding rains triggered a landslide at the Cherry Hills Subdivision in Barangay San Luis, Antipolo City.
The last La Niña event in the countrys was in 2012.
Pagasa’s analysis showed that in April, 23 provinces were affected by the dry spell while 28 provinces, mostly from Mindanao, experienced drought conditions.
A dry spell is defined as three consecutive months of below to normal reduction of 21 percent to 60 percent while drought defined as three consecutive months of way below normal rainfall condition or less than 60 percent reduction from average rainfall.
Pagasa noted that for the month of May, 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 by the end of May showed that 46 percent or 37 provinces will likely to suffer drought; 14 provinces in Luzon, 11 provinces in Visayas and 12 provinces in Mindanao, while 23 provinces may experience dry spell where 17 of these come from Luzon.
Malano said they will continue to closely monitor the dry spell and the developing La Niña.