CAGAYAN DE ORO CITY, Nov. 27 (PIA) -- "We provided information initially for Typhoon Ulysses when it was still a tropical depression. We already issued Severe Weather Bulletin No. 1 as early as Nov. 8, when it developed into a tropical depression."

This was the clarificatory statement made by Dr. Esperanza O. Cayanan, Department of Science and Technology - Philippine Atmospheric, Geophysical and Astronomical Services Administration (DOST-PAGASA) officer-In-charge and deputy administrator for research and development regarding the early warnings released, as Typhoon Ulysses hit the northern part of the country and left Cagayan Valley submerged in floods.

Dr. Cayanan also clarified that the initial warning issued by their office was very early and that it was constantly being updated every 12 hours when the typhoon was still at severe weather bulletin.

As Ulysses developed into a tropical cyclone, wind signal and weather updates were given every three hours. "Twenty four hours before landfall we issued a severe weather bulletin every three hours," Cayanan said.

Despite skepticism on how PAGASA delivered typhoons frecast, the lady chief assured the public that their agency performs very well in terms of forecasting Typhoon Ulysses.

"To give you a performance rating of PAGASA in terms of tropical typhoon track forecasting, we performed very well in Typhoon Ulysses because we have an average forecast track-error of only 38-kilometers compared to the 120-kilometer error allowed by the World Meteorological Organization," she maintained.

Cayanan also elucidated that the Northern Luzon particularly Cagayan [Valley] is not under the wind signals because they are far from the track of the typhoon. However, they had provided rainfall forecast to the dam operators which are around 160 mm of rainfall for the duration of the event compared to the observed rainfall of 158 mm, and according to her was almost a perfect forecast.

As the issue of the Magat Dam releasing water at the height of Typhoon Ulysses, DOST Undersecretary and PHILVOCS Officer In-charge, Dr. Renato U. Solidum Jr. clarified that the issue of dams and the flooding should be carefully assessed and must be based on facts.

"We are preceded by opinions when actually we do not appreciate the real facts about it. For example in the Cagayan River, the discharge of the Magat River is very much smaller than the discharges of many rivers along Cagayan. And in fact, when you look at the rainfall, PAGASA provided the flood advisory on Nov. 8 because the water is rising. The rain started at the lower portion and it is still not raining at the Magat watershed; so the contribution of rain over many other drainage systems leading to the Cagayan River had actually have risen already the flood level before the Magat released. So we have to be very careful in pinpointing the dam operation as to the culprit of the flood," Solidum said.

PHILVOCS head honcho also said that when people will take a look at the rainfall data of Magat, there is no rain before they released water on Nov. 9. However, portions in Cagayan and Isabel are already raining.

"The real problem in the Cagayan River was the restriction in Alcala, it was clogged like a funnel. Unless it was open wide, there will always be flooding with or without the dam," Solidum stressed.

"We cannot say we did not provide a good forecast in terms of the track of the typhoon, the intensity of rainfall, and in terms of warning signals, we issued signal no. 3 which is the actual-observed winds are not too strong but on a lower range of signal no. 3. It is also important to take a look at how the people had reacted to the warning issued," Dr. Cayanan also said.

PAGASA also reminded the public that storms or typhoons have different characteristics. One typhoon signal may vary from another and changes monitored should be looked at carefully.

"When it comes to the movement and speed changes are not seen quickly sometimes. But, once we notice significant changes, we issue a warning or amend the forecast track," she stated.

Both PAGASA and PHILVOCS reminded the public to listen to the warnings and alerts that they issue and to act accordingly based on the advisory issued by their respective local government units (LGUs) and Disaster Reduction and Risk Management (DRRM). A quick response to a warning and alert is important.

"If there is a warning signal we must prepare because we have already been given information," Dr. Cayanan appealed to the public.

The webinar entitled, Understanding Warnings and Advisories issued by DOST-PAGASA and DOST-PHILVOCS on

Nov. 25, 2020 was hosted by DOST-10 in time of the National Science and Technology Week celebration. (JAKArana/PIA10)