The Apocalyptic Riders - Typhoons on the Philippines
.... the day before, the barometer was already fallen and in the radio they issued a typhoon-warning „Signal Number 4“. Now it becomes serious, in about twelve hours, we have to expect the direct draft of a typhoon, Narcing taught me with worried expression and he started with the necessary precautions in order to prevent worse. The roof was checked for leaky spots, some windows got nailed with boards and in the yard several objects were tightened more firmly. In the meantime, other members of the family stocked up the food-supplies, provided some gallons of drinking- and service-water and in expectation of a brownout the refrigerator on ground was put higher and at maximum cold. Carpets were rolled up and the batteries for the radio and the flashlights complemented.
The wind became fresher in the afternoon on and in the east grey-yellow clouds came nearer and nearer. Weather-radiances and lightning threw their lights on the beach for some minutes and with the periodic starting rain the sea colored itself to grey. The clouds darkened more and it began to rain it in swaths and curtains, so that to four meters almost nothing was to be seen. Rolling thunder and the moaning, roaring howl of the winds absorbed each shout. The wind turned into a dreadful tempest, branches of trees got shuttled wildly there and back and the palms were bent in U-shape to the ground. The raindrops changed to projectiles, they flattened shrubs and grasses. The sea cooked and foamed. Then to nightly hour, it became quiet again. Now we are only in the windless eye of the typhoon, Narcing said, that is not yet the end. Typhoons can also come back. And as announced, the infernal scenario started again nerve-racking und faded away the next day. We saw roofs of palms torn away, beheaded palms, in water-ponds standing cottages, strongly swollen brownish influxes to the sea und washed out ways as result of giant force of the typhoon. Narcing began to laugh again and declared that it was only weak typhoon in comparison to others ...
In such a way, a typhoon on the Philippines could be experienced. The personal experience of a typhoon can lead to a generally increased interest in the formation, the further development and the concomitants of typhoons.
Cyclones in the Atlantic and Caribbean area are called hurricanes. In the southeast-Asian area, they are called typhoons. The word typhoon derives from the Chinese word Tai-Fung („strong wind“), from. In Tagalog language, it is called „Bagyo“. Not every storm is declared as typhoon. The „Saffir-Simpson-categories“ - an international classification, which was developed in the fifties – are based on wind-speed. The experts speak from a tropical depression, if the speed of wind is not higher as 63 km/h. Round about half of the tropical depressions in the northwest Pacific and the South China Sea have no further development. If the wind-speed increases up to 117 km/h, then the meteorologist speak from a tropical storm. A tropical storm generates to a typhoon, if the wind-speed of 118 km/h – corresponding wind force 14 - is exceeded. With this standard, the occurrence of a typhoon is defined. Following this categorization typhoons show five subclasses (SS1–SS5) in relation to an increasing wind-speed. SS4–typhoons – also called super-typhoons – have a wind-speed over 208 km/h. With regard to a typhoon of the subcategory SS5 wind-speeds exceed 248 km/h. In this case the waves of the sea are higher than 5,5 meters. People on the Philippines have a good memory for such “century-typhoons”.
While in former times the typhoons were named arbitrarily (for example „Truman“), the Philippine Weather Office publishes since 1963 four lists of names for four years plus additional-cunnings in case that the 19 designated names in each list should not be enough. The list of names – starting with the letter A – refers on abbreviations of female first names, which often end with „ng “. The names of very destructive typhoons are not used again and are deleted from the list. There exists also another register of names for general use in Southeast-Asian countries.
The typhoons influencing on the Philippines develop from extensive low depression-areas with approximately 27 degrees warm, moist, quickly rising air in the western Pacific Ocean (6-12° north / especially the sea area of the Marianas- and Carolinas-Islands). The more the atmospheric pressure falls in the centre, the more cold air begins to flow in from the low atmosphere into the vertically circulating hot-air-system. In South-East Asia – due to the Coriolis-effect (earth rotation) – the moist energy-loaded air-masses turn clockwise in a spiral movement up to ten kilometres. The air condenses in the height and is generating a 100–2000 kilometres wide shield of rain and thunder clouds. Within the ring, there is a circular, wind-poor, often cloudless zone, which is called the “eye” of the typhoon. It has a diameter of 20–100 kilometres. Straight outside the „eye “ there are torrential rainfalls and the strength of wind can reach up to 480 km/h.
By the way an average typhoon produces an energy-quantity of approximately 20 millions megawatts. It is told that this quantity correspondents to the annual electric power production of the United States. And the average rain-quantity of a typhoon reaches nearly half of the rain-fall in Germany. Typhoons have – regardless their strongly destructive effects – also positive or functional qualities for the global weather. They establish a big heat- and humidity transfer system between the tropics and the areas nearer to the polar circles. They lower the temperatures in the tropics and increase them in the polar areas. So typhoons stabilize the global climate-balance.
The westward or northwest to the Philippines moving typhoons appear between July and November – mostly in the months of September and Octobers .
Often, whole provinces, sometimes the half island-archipelago suffer under its effects. Particularly affected are the coastal-areas between northern Luzon and the southern Visayas. The islands Samar and Catanduanes as well as the province Bicol should be mentioned especially. The Sulu-Archipelago, Mindanao, Negros, Cebu, Bohol as well as the south of Palawan, have more luck. They are touched only occasionally by troughs. The “eye” of the typhoon then moves further with 5–25 km/h in western and northwest direction to China, South Korea, Formosa and Japan. Typhoons however can turn back for a short time. Their intensity can increase over the South-Chinese sea again, but on the following land route their destructive effects get a strong reduction because of cooling. The typhoon finally collapses, it „dies “.
The average-duration of a typhoon is round about nine days. However there have been also tornados with two days and four weeks duration.
The number of the typhoons increases on the Philippines. The cause may be the increasing earth warming. In former decades round about 20 typhoons passed annually the Philippines. Now the span increased to 25–35 expected typhoons.
In the Philippines, there are four signal-levels for the arriving of a typhoon. The signals are given by the Philippine Atmospheric, Geophysical and Astronomical Services Administration (PAGASA). In case of the weakest „Signal 1“ the appearance of a typhoon is expected within 36 hours. This period of time is shortened to 24 hours with „Signal 2“. Now wind forces between 60–100 km/h, heavy showers, floods in low situated areas, can be affiliated. If „Signal 3“ is declared - i.e. the expectation of a typhoon within 18 hours - schools, public administration offices and most private offices are closed. Traffic can be regulated. Now wind-speeds with more than 100 km/h are expected. „Signal 4 “ predicts the direct arrival within the next twelve hours. In this case the wind-gusts can have more than 185 km/h and extensive floods can be in store. The warnings levels are based on forecasting, which can be incorrect, for example if the direction of a typhoon changes suddenly.
The 25–35 typhoons on the Philippines cause hundreds of dead, injured or missed persons every year. High also the number of destroyed streets and houses, evacuations, immense the damage through storm-tides and landslides. Harvests, for example coconut harvests can suffer heavy losses and a stronger erosion of soil is often the consequence. Since a gust of 130 km/h can practice a pressure up to 400 kg per cubic meters, roofs are torn away, trees get uprooted and electric- and telephone lines can be destroyed. House-fires are frequent secondary-effects because candles are often used in time of a typhoon - not remembering that the winds are functioning like bellows. The air traffic can get strong restrictions. Also urban areas are affected from floods for example in and about Manila (Tondo, Sampaloc, parts of Quezon city, Valenzuela and Taguig).
Super-typhoons remain a long time in the memory of the people. Here some “Tops”: Super-typhoon Sening in October 1970 reached a wind-speed of 275 km/h. With regard to the typhoons Rosing (1995) and Anding (1981) wind-speeds of 260 km/h have been measured. A stronger wind-speed in the younger history showed only hurricane Gilbert, which destroyed in 1988 Jamaica and parts of Mexico. Here the maximum speed of gusts was 350km/h. – Typhoon Dinang (1981) on the Philippines caused 2764 dead persons. The next followers with regard to the number of victims are Nitang (1984) with 1.363 dead persons and Amy (1951) with 991 victims. The highest number of victims in younger time was recorded from Bangladesh. Here storm-tides in the delta-area caused in 1970 more than 300.000 dead persons.
In 2001 the United Nation's Office for Civilian and Humanitarian Affairs (OCHA) counted in more than 160 countries the casualty figures from earthquakes, typhoons, volcanic eruptions, floods, epidemics, drought, famines, storms, wildfires and landslides in the last 100 years and the Office declared the Philippines as “most disaster-prone country” on the face of earth. Typhoons are a main cause for such a classification.
© Wolfgang Bethge, 2003