By Ellalyn De Vera-Ruiz
Tropical depression “Falcon,” the first cyclone in the country this month, could make landfall over Cagayan province on Wednesday, bringing much-needed rains to a wide area in Luzon and some parts of Visayas.
Philippine Atmospheric, Geophysical, and Astronomical Services Administration (PAGASA) weather specialist Chris Perez said that with the tropical cyclone, wind Signal No. 1 may be raised over some areas in Northern Luzon on Tuesday, July 16.
A weather forecaster of PAGASA shows the current position of Tropical Depression Falcon Monday.
(MARK BALMORES / MANILA BULLETIN)
Around 3 p.m. Monday, Falcon was estimated 1,025 kilometers (km) east of Casiguran, Aurora. It further strengthened with maximum sustained winds of 55 kilometers per hour (kph) and gustiness of up to 65 kph, from 45 kph and 60 kph, respectively, earlier in the day.
From north-northwest, Falcon has slightly changed course, moving northwest on Monday afternoon. But the cyclone continues to move at a relatively fast pace at 25 kph. Should it maintain its current speed and track, PAGASA weather specialist Raymond Ordinario said Falcon may make landfall over the extreme Northern Luzon or over the Batanes group of islands on Wednesday afternoon or evening.
As early as Monday, Perez said scattered to widespread rain showers and thunderstorms were experienced in Albay, Camarines Norte, Camarines Sur, Catanduanes, Sorsogon, Masbate, Biliran, Eastern Samar, Leyte, Northern Samar, Samar, and Southern Leyte due to the trough of tropical depression Falcon.
Meanwhile, the cyclone-enhanced southwest monsoon or “habagat” brought rains over Zamboanga del Norte, Zamboanga del Sur, Zamboanga Sibugay, Maguindanao, Lanao del Sur, Basilan, Sulu, Tawi-tawi, Oriental Mindoro, Occidental Mindoro, Marinduque, Romblon, Palawan, and the rest of Visayas.
Perez said more intense rains will be felt on Tuesday until Wednesday.
This Tuesday, light to moderate with occasional heavy monsoon rains will prevail over Oriental Mindoro, Occidental Mindoro, Marinduque, Romblon, Palawan, Aklan, Antique, Negros Occidental, Capiz, Guimaras, Iloilo, Zamboanga del Norte, Zamboanga del Sur, Zamboanga Sibugay, Maguindanao, Lanao del Sur, Basilan, Sulu, and Tawi-tawi.
Wednesday’s weather
By Wednesday, moderate to heavy rains will be experienced over Ilocos Norte, Ilocos Sur, La Union, Pangasinan, Abra, Benguet, Ifugao, Kalinga, Mountain Province, Apayao, Batanes, Cagayan, Isabela, Nueva Vizcaya, Quirino, Zambales, Bataan, Oriental Mindoro, and Occidental Mindoro due to the combined effects of Falcon and habagat.
Metro Manila
Meanwhile, light to moderate with occasional heavy monsoon rains will prevail over Metro Manila, Aurora, Bulacan, Nueva Ecija, Pampanga, Tarlac, Cavite, Laguna, Batangas, Rizal, Quezon, Marinduque, Romblon, Palawan, Aklan, Antique, Negros Occidental, Capiz, Guimaras, and Iloilo.
Perez said Falcon may further intensify into a tropical storm while it traverses the Babuyan Channel on Wednesday.
A gradual improvement in weather condition is expected by Thursday, as Falcon is likely to be already outside the country’s area of responsibility in the morning, he added.
Angat Dam water level
While tropical depression “Falcon” is not seen to move directly over the Angat Watershed in Bulacan, the southwest monsoon or “habagat” may contribute to the gradual recovery of the water reservoir, PAGASA Weather Division chief Esperanza Cayanan said.
Angat Dam needs at least 350-millimeter (mm) of rainfall to reach its 180-meter minimum operating level, according to the state weather bureau.
Since the past week, the water level at Angat Dam has continued to decline and remains below its 160-meter critical level.
As of Monday morning, Angat Dam’s water level was 158.75 meters, down by 40 centimeters from last Sunday’s 159.15 meters.
Water from 4-5 cyclones
Angat Dam needs at least 1,160 mm of rainfall, equivalent to four to five cyclones, to reach its 210-meter normal high water level, Cayanan said.
From Tuesday until Wednesday, monsoon rains may contribute about 150-mm rainfall over the Angat watershed in Bulacan.
“So far, our forecast shows that the rainfall over the watershed will not reach the 350-mm rainfall from monsoon rains alone, but there are still thunderstorms that may also help increase the Angat Dam’s water level,” Cayanan explained.
Citing the PAGASA’s historical record, she said Angat Dam’s level usually normalizes towards the end of July to early August.
Two to three cyclones usually affect the country in July, two to four in August, and two to four in September.
Once the Angat Dam reaches its 180-meter minimum operating level, the National Water Resources Board may increase the water allocated for Metro Manila’s domestic requirements.
The current water allocation of 36 cubic meters per second (cms) is split 60-40 to water concessionaires Maynilad and Manila Water, respectively.
The normal water allocation for the domestic requirements of consumers in Metro Manila and nearby provinces is 48 cms.