UP Ibalon Bicol: Typhoon 'Auring'

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Sea State: A New But Needed Concept

1/16/2009 | Posted by myty555 | Edit Post

No, the term sea state does not refer to some group of atolls in the Pacific or Indian oceans that comprises a small state. This instead refers to the state of the sea much like a weather forecast.

The Philippines, though a maritime country, does not use this concept. At least not in weather forecasting. But events of the last few days and during the first days of January points to the need of using this concept. Repeated suspension of ferry sailing and floodings have been frequent recently [see: "Wicked Weather Count: 2,500 Stranded in Bicol, 50 Homes Destroyed in Cebu, 16,000 Flood Evacuees in Agusan del Sur", 1/15/09]

Let's face it. Small ships and fishing vessels sink even without a storm warning, like now. It is because seas can be too rough if the monsoons are in full swing. Like now. But there is a crucial lack of forecasting the state of the seas or sea state.

A sea state refers to the height, period (the two components of a wave in physics) and character of waves of a large body of water (waves can be said to be confused which makes it more dangerous). The strength of the wind is just one factor in creating a sea state. The monsoon swell is another. And tides play a factor, too.

PAGASA, out local forecaster uses the term sea condition. It bases its reading on the old Beaufort wind scale but with 9 gradings (The modern Beaufort wind scale has 12 gradings with the additional grades 13-16 to describe strong tropical cyclones; but some countries even use the 17th grade to describe phenomenal wind forces).

The beauty of an integrated Beaufort scale is that it not only describe wind strength but also the sea conditions including wave height. This is the failing of tropical depression/typhoon forecast we use locally that has only 4 grades and is just the measure of the wind strength, basically.

One small advancement, at least, of PAGASA is that they now use the concept of a gale which is a very strong wind. A full gale, at 63-87kph generally describes our Typhoon Signal #1. So sometimes when PAGASA forecasts gale it is actually describing near-gale winds (not now because half of Philippine seas are under gale conditions and that is why there are waves that are in the range of 3.7-7.0 meters which is more than enough to cancel the trips of regional ferries [not the inter-island ferries from Manila]).

However, more advanced countries than us have sea state forecasts aside from tropical cyclone warnings. Rather than relying on transmissions from passing ships and coast watchtowers it now uses satellite imagery. Shouldn't we be subscribing to these services? If the government can hardly procure Doppler weather radars there is no way we can launch a dedicated weather satellite.

The World Meteorological Organization (WMO), a specialized agency of the United Nations has a sea state code. Other countries have their own systems. Even NATO (North Atlantic Treaty Organization) has their "Definition of Sea States" and this one even has modal periods (period between waves). I have seen sea state definitions that even traces different causal conditions which is one reason for the dangerous conditions called confused waves (conflicting waves). With an understanding of the theory of modal periods collosal (or rogue) waves, which capsize boats and launches, can be anticipated.

It seems we are a little bit behind the times.

[Note: Images above describe a full gale or Force 8 on the Beaufort scale]

[Images credit: brianlean, lavoieverte]

Labels: Beaufort scale, Doppler radar, Force 8, gale, monsoon, near-gale, PAGASA, rogue wave, sea condition, sea state, Typhoon 'Auring', WMO

Storm Signals Lowered, Coast Guard Suspension of Trips Remain, The Classic Conflict and Ten Thousand Stranded in Bicol

1/04/2009 | Posted by myty555 | Edit Post

As of 4:30pm today, Sunday, January 4, 2009 Typhoon 'Auring' has changed direction to the North and it will no longer hit land. Consequently, all public storm signals have been lowered except for Eastern Samar.

If there are no storm signals prevailing, normally ferries can set sail. However, for prudence's sake, the Philippine Coast Guard maintained its suspension of sea travel at 10 points. That will mainly be in Bicol, Eastern Visayas and Caraga region.

Reports say over 10,000 people are stranded in Bicol. I will not be surprised if the total number of people right now reaches 30,000 all over the suspension areas.

I have said in a previous article that it is wave heights that primarily matters and not wind speed ["Two Boat Sinkings, A New Year Ferry Suspension in Bicol, Wave Height and Gale, 01/02/09]. But I checked the PAGASA forecast and there is no mention of wave height! It is Mike Padua's weather service website 'www.maybagyo.com' that has a wave height forecast but it is just near the typhoon's center.

So nobody knows right now how large the wave will be in the ferries' routes. Though PAGASA enjoins ships to report meteorological conditions in their specific areas I don't know if this is heeded. And if heeded I don't know if PAGASA has a way of consolidating and disseminating it.

This is the borderline area that produces sea accidents. Of course, ship companies would want to sail. In the case of overnight ferries to Cebu if they don't sail they probably won't have a ship available for the next night because none arrived. And this throws awry their set schedules.

As I write this it is the time for peak departures of ferries. These departures are usually bunched between 7 to 8pm. I know that they will be trying to break free of the Coast Guard leash and try to sail even by midnight tonight so they can still meet their sked tomorrow. So sometimes this becomes a cat-and-mouse situation. If the seas are rough in their ports, the captains may not turn out bull-headed at all. But if it is calm, he will be at the face of the local Coast Guard commander, who in many cases is not of officer rank. But, of course, he will have no way of knowing how strong are the seas in his route.

The situation points out one problem in the Philippines. Even in Spanish days we have watchtowers who are able to observe local sea conditions. This was reinforced by the Americans. Part of this system are the lighthouses. However, in recent decades the old watchtowers started to crumble and some of the lighthouses are already automated, meaning there is no one manning them.

But the problem is this system is not under PAGASA but under the Coast Guard and it is PAGASA that makes the forecasts. Moreover, many of these lighthouses have no communication to a data collection point. Sayang (a waste), because anyway many of these have cell site coverage. And big ships are anyway sailing but I wonder if reports from them are assidously followed up.

Old England has a system of coast watchers. Don't we need to emulate it given our long coastline and reliance on the seas?

I will be interested in the further development of this discourse. This is a safety at sea question where people, especially the sailing public, should be interested in.

[photo credit:daylite]

Labels: 10000 stranded, 102nd, bicol, Coast Guard, Eastern Samar, lighthouses, magbagyo.com, Mike Padua, New Year ferry suspension, PAGASA, Typhoon 'Auring', watch towers, wave height, weather forecas

UP Ibalon Bicol

Sea State: A New But Needed Concept

Storm Signals Lowered, Coast Guard Suspension of Trips Remain, The Classic Conflict and Ten Thousand Stranded in Bicol

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