Did a squall cause MV Trisha Kerstin-3 sinking?

Did a squall cause the sinking of the MV Trisha Kerstin-3, killing 18 people?

Coast Guard spokesman Capt. Noemie Cayabyab said a squall is one of the angles being eyed in Monday’s sinking of the passenger ferry, which had over 332 passengers on the manifest.

She described a squall or subasko as a sudden strong gust of wind and waves that causes boats to capsize.

“Itong squall o subasko, hindi nade-detect nang PAGASA. Bigla itong makaka-experience sa area ng sudden increase ng windspeed, biglang lalakas din ang alon,” she said in a DZMM interview.

She added that squalls have been reported not just in Baluk-Baluk Island in Basilan but in other provinces. “There are times that it causes maritime incidents,” she said.

Sailors’ experience with squalls are usually similar, she said. "Kinukwento ng crew na umalis sila sa pantalan na kalmado ang dagat tapos pagdating sa gitna biglang makaka-experience ng malakas na hangin at alon,” she said. 

According to PAGASA weather forecaster Benison Estareja, a squall or subasko is a small-scale localized thunderstorm that occurs in both wet and dry season.

He noted that it is hard to determine if there was a squall near Baluk-Baluk island based on satellite data during the time of the sinking.

“Meron kami nakita lang ng mga high clouds, meaning ‘yung mga high clouds na yan, parang hindi po siya nagpuproduce talaga ng storm. So ‘yung squall itself, it's still not verified as of now,” he said in a separate

“Wala po na clouds kami mamataan kasi doon sa paligid ng Basilan at saka po ng Zamboanga City,” he added.

Altimeter data in nearby weather stations, however, recorded wave height of 1 meter, which can rock a small bot but will have minimal effect on a medium or large vessel.

Squalls occur more frequently in middle latitude countries with cold weather, Estareja said.

“Kung sa middle latitudes, meron tayo nakikita mga squalls na tatagal na mga hours. Unlike dito sa tropics, lalo na ‘yung malapit po sa equator, mga short-lived lang po talaga ito or mga sudden lang ng mga storms or mga gusts of wind. In the case dito sa parteng Basilan, malapit na talaga sa equator,” he said.

He noted ships capsizing because of a squall are rare in the Philippines, adding there might be other reasons why the ferry sank.

In the interview, Cayabyab said a PCG diving team will continue to check the area where the ferry sank for possible survivors.

“We have not downgraded to search and retrieval. Pwede nagdrift sa islands or coastal areas. Sometimes we still find survivors after 2 weeks,” she said.

Divers will also check the appearance of the MV Trisha Kerstin-3 for clues on what caused it to sink.