La Niña to cause heavy rains until September–Pagasa

MANILA, Philippines – La Niña ended in the Philippines in June but would continue to make its presence felt through heavier rains up to September, the country’s weather bureau announced on Wednesday.

And with this, Ondoy-like rains remain a possibility, said Science undersecretary Graciano Yumul, who supervises the Philippine Atmostpheric, Geophysical and Astronomic Services Administration. Yumul noted that there was also La Niña in the country in 2009.

“The southwest monsoon would last until September. So when a storm makes landfall and combines with the monsoon, and they bring heavy rains, it would be Ondoy-like,” Yumul said.

This was what happened with Tropical Storm Ondoy, which directly hit Luzon in September 2009. Ondoy’s rains, coupled with the monsoon, submerged most of Metro Manila, killing hundreds.

Yumul added that La Niña’s residual effects would usually be felt three months after it left. This means that the country would experience heavier rains, whether it would come from a typhoon, a storm, a low pressure area, the tail end of a cold front or any other weather disturbance.

“What does La Niña bring? A lot of water. So now, in all that had happened – the cold front, southwest monsoon, ITCZ – there has been a lot of water,” he said.

La Niña, which translates to “little girl” in English, refers to the abnormal cooling of sea surface temperature in the Pacific. In the Philippines, this phenomenon causes more rains.

Nathaniel Servando, head of the Pagasa, said that the weather bureau has been expecting stronger storms. The number may even go up to 20 to 21, a little over the average of 19 to 20 that hit the country in a year.

Yumul also said the heavy rains being experienced in the country could be attributed to global warming as well. With the rise in global temperatures, more water evaporates, and what would be brought up should go down, he added.

He noted that the situation in Mindanao, which has been wet in the past few weeks, has been part of this. Mindanao is usually the drier part of the country, but recent weather disturbances have affected it, he noted. Northern Luzon, in contrast, has been dry, he added.

“Usually, there are heavy rains during typhoons, but now even during a low pressure area [the same is felt],” he said.

Yumul also said the rains that had caused flashfloods in Davao were due not to any typhoon or even a low pressure area, but to the intertropical convergence zone, a weather disturbance that has been the breeding ground for storms.

He said the flashfloods could have been caused by clogged waterways. Even if the rains were heavy, floods would not happen if water could flow freely, he said.

As for the floods in Central Luzon, Yumul said these could be attributed to tropical depression Egay.

He said Egay’s onslaught led to a “supersaturation” of the ground in the region. When Falcon came and caused the southwest monsoon to bring more rains, the ground could no longer absorb the moisture.

As for Calasiao, Yumul said this was the catch basin of Pangasinan, which was why water flowed toward it.

Yumul said people should be aware of the changing weather patterns in their areas so that they could prepare for floods or landslides.

Ronald Flores of the National Disaster Risk Reduction Management Council also said that local government units should take note of the changing weather patterns so that they could adjust their disaster plans.