Friday, February 12, 2016

Expect drought, dry spells due to ‘strong’ El Nino until June

It’s now official:  the El Nino dry and hot weather will continue to bring drought and dry spells until summer. 

Recent observations show that the sea surface temperature anomalies in the equatorial Pacific are still beyond 1.5 degrees Celsius warmer than the average, indicating a “strong El Nino event”, the Philippine Atmospheric, Geophysical and Astronomical Services Administration (PAGASA) declared yesterday.

The El Nino weather is “likely to persist until the second quarter of 2016,” said Dr. Vicente B. Malano, PAGASA Administrator. “The adverse impacts include below normal rainfall that could lead to a dry spell and drought conditions in many parts of the country until the first half of 2016.”

PAGASA defines “drought”, in the weather sense, as three consecutive months when more than 60 percent reduction from the average has been observed. Drought also occurs when five consecutive months of below normal rainfall (21 percent to 60 percent reduction from average) has been observed.

A dry spell occurs when below normal rainfall (21 percent to 60 percent reduction from average) have been observed for three consecutive months or when two consecutive months of way below normal rainfall (more than 60 percent reduction from average) occur.

“El Nino is still there and its impacts will continue,” Dr. Malano said in a press briefing, adding that hotter or “warmer than normal” air temperatures are likely to be felt.

In response, “PAGASA started cloud seeding operations over Angat Dam even before the two typhoons hit in December,” said Dr. Landrico U. Dalida Jr., PAGASA Deputy Administrator for Operations, adding P79 million has been appropriated for cloud seeding. “We have shifted cloud seeding now to Mindanao and the Visayas which are suffering from drought.”

A strong El Nino will delay the start of the rainy season, coming in July instead of June this year, said Anthony Lucero, head of PAGASA’s Climate Information Monitoring and Prediction Section.

The monsoon rains will be weak to the point that rainfall will be “below normal”, extending the   dry season, he said. However, despite the dry weather, two to six tropical cyclones may develop or enter the Philippines from now until June, he added.

Already, Mindanao and the Visayas have had very little rains, said Dr. Flaviana D. Hilario, PAGASA Deputy Administrator for Research and Development. The “below normal” rains prior to November observed nationwide was interrupted with above normal rains in Luzon in December, especially after typhoons Nona and Onyok occurred in December.

“The El Nino expected to will remain strong until February with the probability of below normal rainfall expected from January to April, leading to drought in 68 provinces by the end of April,” said Lucero. “Slightly warmer than average temperature is expected during the period.”

The strong El Nino was first observed in mid-July 2015, growing into a very strong El Nino in November.

The chances are “favorable for El Nino gradually decreasing from May to July,” Lucero said.  The Northeast Monsoon season experienced from January to March will transition to the   Southwest Monsoon and will bring local thunderstorms and tropical cyclones from April to June, he said.

Still, 20 percent will likely experience drought 16 provinces, he said. By the end of February, 36 percent of the country affecting 29 provinces will experience drought until the end of February, he said.

By the end of March, 44 provinces (42 percent of the country) will experience drought and dry spells. By the end of April, 85 percent of the country, affecting 68 provinces, will experience drought.


The start of the rainy season by the end of May will bring down to just 34 the number of provinces that will experience drought. By the end of June, 18 provinces will continue to have drought. (SciencePhilippines)

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