Last October 18 2015, Tropical Cyclone Lando (Koppu) brought heavy to intense rain showers in Luzon as it traversed slowly towards Northern Luzon—just in time when water levels in the region’s major reservoirs were threatened because of the El Niño.
Yearly, an average of 18 to 20 tropical cyclones enter the Philippine Area of Responsibility (PAR), and 50% of our water supply come from rain showers brought mostly by these weather disturbances.
According to the Philippine Atmospheric, Geophysical and Astronomical Services Administration (PAGASA) together with other international meteorological agency, El Niño phenomenon happened in 1997 is being considered as the worst El Niño event where damage in farmlands reached P3 billion.
Before Lando, the Angat dam has been struggling with relatively low water levels since March that had eventually led to a decreased water supply in Metro Manila.
Today, as the Angat dam finally regains normal water levels, the National Water Resources Board continues to implement the proper allocation for water concessionaires to be able secure water supply until the next dry season.
Dam Data
Here’s a quick look at Luzon’s Major Dams:
Angat Dam – Situated in Norzagaray in Bulacan, it supplies water to farmlands in Pampanga and some parts of Bulacan, and is a power source of the Luzon grid. Metro Manila and Bulacan residents also get their water supply from here. During the rainy season, the flood season water level of Angat Dam is at 210 meters, while the dry season normal high water level is at 212 meters.
Ipo and La Mesa Dams – These dams are part of the Angat-Ipo-Lamesa water system. Located in Norzagaray, Bulacan, the Ipo dam water is diverted to the Novaliches portal and the La Mesa dam. The latter is situated in Fairview, Quezon City. Its main purpose is to provide water for domestic use in Greater Metro Manila.
Ambuklao Dam – Found in the mountains of Bokod, Benguet, this was designed to provide 75 MW (megawatts) of energy to the Luzon grid. Water level in Ambuklao dam also varies depending on the season. The normal high water level during dry season is at 750 meters while the flood season water level during rainy season is at 752 meters.
Binga Dam – Found in the province of Itogon in Benguet, this dam forms an impoundment on the Agno River. It’s also a hydroelectric plant that supplies power generation to nearby provinces. Binga dam maintains a 575-meter level regardless of the season.
San Roque Dam – Spanning from San Manuel and San Nicolas in Pangasinan, this is among the largest dams in the Philippines. Connected to the Tarlac River through the Agno River, the San Roque dam provides irrigation to San Manuel, Asingan, Sta. Barbara, Binalonan, Urdaneta City, Villasis, Calasiao, Mapandan, Manaoag, Mangaldan, Laoac and Malasiqui. It also supplies power generation to Luzon grid. Normal water level in San Roque dam is at 280 meters.
Magat Dam – Magat dam rests in the province of Isabela, and is located specifically in the Magat River, considered the largest tributary of the Cagayan River. As one of the largest dams in the Philippines, its primary purposes are providing irrigation and hydroelectric power to 85,000 hectares of agricultural lands in the Cagayan Valley and other parts of the Isabela province.
Caliraya Dam – Positioned along the Caliraya River in Lumban, Laguna, and this dam utilizes water in the Caliraya River Basin. The power generated from the Caliraya Hydroelectric Plant is intended for the Manila power market.
Light rains will prevail in Batanes, Calayan and the Babuyan Group of Islands due to the Northeast Monsoon or hanging amihan affecting the extreme Northern Luzon. Meanwhile, the trough or extended part of a Low Pressure Area (LPA) continues to affect the province of Palawan, where cloudy skies with light to moderate rains and isolated thunderstorms are expected. Metro Manila and the rest of the country will experience partly cloudy to cloudy skies with isolated thunderstorms.
PAGASA Weather Forecaster Gener Quitlong says the LPA in the West Philippine Sea has a slim chance of intensifying into a tropical cyclone within the next 24 hours. The LPA is also expected to head towards Southern Vietnam, moving farther away from our country. Aside from this LPA, no other weather disturbance is being monitored outside the Philippine Area of Responsibility (PAR).
Due to the presence of amihan, gale warning remains in the northern seaboard of Northern Luzon, where wave height ranging from 3.4 to 4.5 meters and wind force of 52 to 63 kilometers per hour may occur. Sea travel is still risky for fishing boats while larger sea vessels are alerted against big waves.
Amihan vs. Habagat
During the past few months, the Southwest Monsoon or habagat affected the country, dumping rains mostly in the western section of the Luzon. Many areas suffered from flooding due to the heavy and occasionally intense rainfall especially during the passage of a tropical cyclone.
Early this October, PAGASA has observed the weakening of the said wind system. Along with this, the high pressure system over the Asian continent was also observed, leading to the entrance of another wind system – the amihan.
Amihan is characterized by cold and dry air coming from Mainland China and Siberia. It usually brings lower temperatures and slightly cold weather to the country. However, its peak normally occurs during January or February.
Easterlies, winds coming from the east that are warm and humid in nature, are now affecting the eastern part of the country, resulting to rain showers mostly in the eastern part of Luzon, Visayas and Mindanao.
Light to moderate rain showers brought by easterlies will be experienced in Visayas, Bicol Region, CARAGA, Northern Mindanao, Davao Region, Zamboanga Peninsula and in the provinces of Quezon and Palawan.
Meanwhile, another wind system is extending in the extreme Northern Luzon. Light rains due to the northeast monsoon or amihan is expected in Batanes, Calayan and Babuyan Group of Islands.
#walangpasok : Asia Pacific Economic Cooperation (APEC) Summit 2015
In connection with the upcoming Asia Pacific Economic Cooperation (APEC) meetings this November, work and classes in all levels in National Capital Region (NCR) are suspended on November 17-20, 2015.
After the preparations for All Saints’ and All Souls’ Days, one must also be prepared for what November weather will bring. Here are the top 3 things you should know about the 11th month of the year!
1. Not so cool, not so wet
With the El Niño phenomenon solidly in place, we can expect reduced rainfall in most parts of the country. Latest reports from PAGASA and other international meteorological agencies have observed evidences that this year’s El Niño may be one of the strongest in history. It is more likely to continue until the end of this year, and might last up to June 2016. If we look at the forecast for November’s rainfall, the western part of Northern and Central Luzon may experience way-below normal rainfall, while most parts of the country may have below-normal amount of rain.
The El Niño may also bring a continuous rise in temperature, along with hotter and more humid weather. Being just a month before Christmas, November may not be as cold as what we’re used to. The northeast monsoon has yet to intensify because its peak usually occurs during January or February.
Meanwhile, based on the forecast of PAGASA, the highest number of dry days may be experienced in the eastern section of Luzon with a range of 26 to 31 days or almost the entire month.
2. A chance of a weather disturbance
Different weather systems are expected to affect the country this month. These include the northeast monsoon, tail end of a cold front, easterlies, ITCZ, low pressure area (LPA) and tropical cyclone.
The northeast monsoon, locally known as “amihan,” will prevail particularly over the areas in Luzon. Amihan will reach the Philippine Area of Responsibility (PAR) once the high pressure system over Mainland China or Siberia intensifies. Aside from light rains, it will bring slightly cold and dry weather to the affected areas. However, its surge may not be strong yet.
The Tail End of a Cold Front is the extended part of a frontal system. A Cold Front is a boundary of cold and warm air masses. This weather system could result to rains and thunderstorms due to the convective clouds.
Easterlies are winds coming from the Pacific Ocean, and are warm and humid in nature. It may bring warmer weather but could also trigger thunderstorms mostly in the eastern section of the country. Remember, heat is a key ingredient for thunderstorm formation.
The Intertropical Convergence zone (ITCZ) may still be present so a Low Pressure Area could also be formed. An LPA may then develop into a tropical cyclone or “bagyo”.
According to PAGASA, an average number of 1 to 2 cyclones may enter the PAR this month, with a chance of making a landfall or re-curvature.
3. Get ready, sky watchers!
The Leonids Meteor Shower is expected to show up in the sky this November. The National Aeronautics and Space Administration (NASA) says it is called such since it seems to originate from the constellation “Leo”.
It will be active on November 5 until the end of the month, with peak activity on November 17 to 18 this year. If weather permits, one can observe around 15 meteors per hour at a speed of 71 kilometers per second.
Did you know?
In an average of every 33 years, the Earth may experience a Leonid Meteor Storm. Compared to a shower, it is defined as having at least 1,000 meteors per hour.
In 1966, viewers were able to witness a spectacular Leonid Storm where thousands of meteors fell through the atmosphere. NASA says the last Leonid Meteor Storm occurred in 2002.
Mentioned above is just an overview of what may happen this month. The weather and sky conditions continuously change so make it a habit to monitor updates.
Sources:
PAGASA-DOST
NASA
The Philippine weather bureau PAGASA said, the northeast monsoon (locally known as amihan) has only just begun reaching the extreme Northern Luzon.
Meteorologist Aldczar Aurelio explains that it’s only t the start of the northeast monsoon or amihan season, still with the presence of the El Nino.
Eventually, the northeast monsoon will be experienced in the metro in the coming months. It usually peaks during January and February, but with the effect of El Nino, Aurelio said this season will be slightly warmer compared to last year.
The lowest temperature last season was 9 degrees Celsius, and was recorded at Baguio City on February 10, 2015.
Today, amihan will bring light rains in Batanes, Calayan and the Babuyan Group of Islands, while the Bicol Region, Eastern and Central Visayas, CARAGA, Northern Mindanao, Davao Region, Zamboanga Peninsula and the province of Quezon will have cloudy skies with light to moderate rains brought by easterlies.