TORNADO TALES

A TRAIL OF TRAGEDYIt came without warning. Ferocious and violent. It lasted for just a few very terrifying minutes…and then it was gone. The unreal calm that followed was in utter contrast to the devastation it left in its wake. In time, the calm was pierced by the cry of an infant. She was fortunate. She had survived. She had not been sucked into the vortex of the debris created by one of the most wrathful of weather monsters: the tornado..Just before sunset on 13 May this year, the tornado roared into the Tangail-Jamalpur area of central Bangladesh, some 100 km north of Dhaka. It was the worst in recent memory. Standing crops were snatched into the air. Houses were smashed, their tin roofs pulled into all directions. Trees were uprooted. Power connections were snapped..The ´twister´ which ripped across the countryside at a mind-boggling 200 kms per hour, reduced 80 villages to indistinguishable rubble. Raging debris killed over 700 men, women and children. More than 34,000 were wounded. Crushed limbs, skull fractures, lacerations and contusions were the commonest injuries. In some cases, rice grains had flown with such intense speed that they had punctured and penetrated human flesh like so many thousand stumpy needles. Almost everyone in the 15 km path of the tornado received some injury—major or minor..When they saw the clouds gathering, the inhabitants of Tangail thought it was another nor´wester in the making. In Bangladesh, summer is the time for nor´wester or kalboishaki storms which are characterised by strong winds and crashing, pelting thunderstorms. People rush for cover when the kalboishaki comes. Once the storm passes, it is business as usual. Nor´westers are not necessarily friendly, but they are an inevitable feature of the hottest months. They are even welcomed because they bring respite from the oppressive heat..It is for this reason that the few people who did hear the storm warning on 13 May did not pay too much attention to their radio sets. In any case, May is a busy month for peasant farmers who work from dawn to dusk harvesting paddy. This activity proved to be fateful this year, for most of those who were outdoors on the day that the tornado struck, were either injured or killed. As they scrambled for shelter they were battered unmercifully by a variety of airborne missiles—branches, stones, razor-edged tin roofs, household items…anything that the winds could uproot or unfasten..THE SURVIVORS.Forty-year-old Zarina of village Koilla was cooking the evening meal when she suddenly heard a furious wind. She ran out of the house and found that the sky had turned a fiery red. A huge chunk of earth flashed past her. "I have never seen such a violent storm in my whole life nor ever heard of anything like this," she said in a voice choked with emotion. All of Zarina´s three sons were badly injured..In the village of Mirikpur, 10-year-old Nanda courageously threw himself over his sleeping baby sister Mukti. She survived. Her brother, in shielding her, received serious head injuries. Their parents did not live to see them. Nanda and Mukti´s father was crushed under a falling tree and their mother buried under the rubble of a collapsed portion of the house..Perhaps some of Nanda´s friends were among the children of Mirikpur Gangacharan Tafshili High School who were killed when the building they were in came crashing down. There were innumerable other distressing stories. Widowed men and women, orphaned children and bereaved families everywhere—dazed and uncomprehending. In the time that it took for the storm to pass, lives were changed permanently and minds scarred forever..It will be a long time before the survivors of the Tangail tornado can piece together their shattered lives. The blow of their personal tragedies was somewhat softened by the spontaneous assistance and care offered by their neighbours from unaffected areas as well as by governmental and non-governmental relief teams. The tornado victims needed all the help they could get..Everything had been swept away by the howling winds—their houses, food, the utensils they used for cooking, their savings, children´s school books, clothes, everything..Shamsuzzaman, a photojournalist who visited some of the tornado-hit villages a week after the disaster had this to say: "I was deeply impressed by the resilience of the people there. They had lost all that they possessed and yet there seemed to be a strong sense of determination among them…the resolve to make a new beginning was almost palpable.".UNDERSTANDING TORNADOES.Meterologists and scientists tell us that although they have been studying the tornadoes for a long time, much still remains to be learnt about the phenomena. The word tornado comes from the Spanish tronada (thunderstorm), derived from the Latin tornare (to make round by turning)..The tornado is the most violent of atmospheric storms that are caused by low air pressure. It consists of a powerful vortex or "twister", whose speed as it spins about can easily go up to 480 km per hour, and in some instances may exceed 800 km per hour. The intense updraft that occurs near the twister´s centre is capable of lifting quite heavy objects such as trees and cars into the air and of upending even heavier objects such as railway cars or aircraft..There is relatively low pressure right at the centre of the tornado´s funnel-like vortex. This causes cooling and condensation, thus making the storm visible as a revolving column of cloud, called the funnel. The lower portion of the tornado funnel often appears as a mass of dust and debris picked up by the vortex. The rim of the funnel is usually rendered visible by clouds produced by the condensation of water vapour. The path of the average tornado averages only 700 metres in width (although there can be great variation), but they can travel over tens of kilometres wreaking havoc before they lose strength..Tornadoes are generated from severe thunderstorms, which form readily when warm, moist winds clash with cool, dry ones. The precise atmospheric requirements involved in the generation of tornadoes, however, are not completely understood. Tornadoes often form a line of thunderstorms along what is known as a squall line and generally travel from southwest to northeast, although those that develop from tropical cyclones travel from east to west..Besides Bangladesh, countries reporting tornadoes include Australia, Great Britain, Canada, China, France, Germany, The Netherlands, Hungary, India, Italy and Japan..The first visible indication of tornado development is usually a funnel cloud, which extends downward from the cumulonimbus cloud of a severe thunderstorm. As this funnel dips earthward, it becomes darker because of the debris forced into its intensifying vortex. Some tornadoes give no visible warning until their phenomenal destruction strikes down on the unsuspecting victims..The areas with the greatest potential for casualties are those that combine a high tornado incidence with a thick population concentration. Tornadoes may occur any month of the year, but are most numerous in summer. Although they may strike at any hour of the day or night, they generally form during the afternoon or evening, between 3 pm and 7 pm, which is the period most favourable for the development of the severe thunderstorms from which they are bred..According to Mir Fakhrul Qayyam, the Director of Bangladesh´s Meterological Office, there is no established mechanism to measure the strength of the tornado. Indeed tornadoes destroy all standard measuring instruments, hence most values given for velocity, pressure and energy distribution have to depend on theory and estimates of structural damage after the event..Some advances have been made in tornado detection and warning systems, including analysis of surface and upper air weather, detection and tracking of atmospheric changes by radar, and spotting severe local storms. At the same time, many more ways of gathering and communicating information about tornado formation and movement need to be developed, in order to help people take appropriate precautions..Virtual Vortices.Hollywood´s latest offering is a purely illusory, digitised tornado. Film director Jan De Bont´s Twister is Hollywood´s latest blockbuster offering. It follows on the trend of films having menacing non-human protagonists which was started by the film The Towering Inferno (fire), and continued by films like Earthquake, jaws (sharks) and Swarm (bees)..The central ´character´ of Twister is a computer-generated tornado. The film cost USD 85 million to make and harnessed the talents of 60 computer-graphic artists from Industrial Light and Magic company of Northern California—the number one special effects (FX) house of the United States..While the ´human´ parts of the film was shot on location in Oklahoma, which is hit by natural tornadoes all the time, the real work of creating fake clouds, wind vortices and whirling debris was done at a high-power Silicon Graphics work station. Altogether, 25 minutes of storm scenes were fabricated digitally and combined on film with real actors and location footage..Newsweek (20 May, 1996) warns, "Don´t try this on your laptop; Twister´s shots take up to 17 trillion bytes (equivalent to about 12 million floppy discs) of memory. The state of art FX cost 15 million dollars.".Ironic isn´t it, that while some people lose everything they have to real tornadoes, others create artificial ones to improve their material well-being?