Amihan saps Ruby's strength, but typhoon still going strong

By ROSE-AN JESSICA DIOQUINO, GMA News

Published December 5, 2014 7:30pm

The northeast monsoon (Amihan) is influencing how Typhoon Ruby is shaping up as it approaches the country, with the monsoon's cold air weakening the storm slightly as the latter makes its way towards Eastern Visayas.

However, it continues to be a strong typhoon, with winds of up to 195 kph.

Interaction with Amihan

In the 4 p.m. bulletin of state weather agency PAGASA, acting administrator Vicente Malano explained that the storm's strength is directly affefcted by the surrounding environment, particularly the northeast monsoon.

He explained: "Sa panahon ngayon, meron tayong tinatawag na hanging Amihan o northeast monsoon. Nanggaling po 'yung hangin na 'yan sa Siberia. Meron pong tinatawag na high-pressure cell at nakarating yang hangin na 'yan at nag-impluwensya't nag-interact (kay) Ruby."

Like most storms, Amihan is driven by the circulation of warm air. But interaction with the Amihan has affected the overall temperature of the air in Ruby's system, weakening it slightly. As a result, Ruby's winds have slowed from 215 kph to 195 kph and its diameter has decreased from 700 km to 600 km.

Cold, dry air

Malano also said that the Amihan's dry air is also contributing to Ruby's slowdown.

"Dry air kasi 'yung hangin na 'yan, so wala siyang moisture... Ang pagkain kasi ng bagyo ay moisture, so [with Amihan] hindi nasu-sustain 'yung energy kundi nababawasan," he explained.

Malano added: "'Yun 'yung inaasahan nating magpe-prevail, 'yung hangin na nanggaling sa Siberia, na mag-iimpluwensiya doon sa pag-develop at pag-dissipate o pag-weaken ng bagyong Ruby. Inaasahan natin na within the next 24 hours ay mag-influence pa rin 'yun at inaasahan natin na dahil sa impluwensiya ng malamig na hangin sa bagyo ay hihina pa ito."

Water volume

The Amihan is also expected to slightly decrease the volume of water brought by the storm, Malano said.

While this development does not assure that there will no longer be storm surges, he said, "'Yung storm surge na sinasabi natin ay very much dependent kung gaano kalakas 'yung hangin. Ang storm surge ay very much dependent din kung ano 'yung configuration ng bay [na daraanan]."

Hoping for delay

DOST Secretary Mario Montejo said he hopes that Ruby slows down long enough for the Amihan to prolong this weakening effect on the system.

"The longer na mas magtagal siya, mas advantageous," Montejo said.

"Habang tumatagal, lalong humihina. It will weaken until and after landfall, so 'yun ang positive news. Hindi na siya magiging super typhoon," he added.

Current location

A 4 p.m. tweet by radio dzBB said Ruby's winds were less powerful at 195 kph.

As of 3 p.m., it was estimated at 380 km east of Borongan, Eastern Samar.

In a press briefing, PAGASA said Ruby was located at 380 km east of Borongan, Eastern Samar, with maximum sustained winds of 195 kph near the center and gust of 230 kph.

It is expected to move west-northwest at 13 kph. — With TJ Dimacali, GMA News

Tags: hagupit, ruby, amihan