Sidr was one of the fiercest cyclones
Sidr was considered as fierce a cyclone as the ones that hit the country in 1970 and 1991 killing 5 lakh and 1.4 lakh people respectively
The cyclonic storm of hurricane strength, Sidr, was one of the 10 fiercest cyclones that had hit the region of Bangladesh in the 131 years between 1876 and 2007. The combined death toll in those storms stands around one million people, according to the records of the meteorological department.
Sidr was considered as fierce a cyclone as the ones that hit the country in 1970 and 1991 killing 5 lakh and 1.4 lakh people respectively.
The highest wind speed of Sidr, meaning 'hole' or 'eye' in Sinhalese language, was recorded in Patuakhali at 223 kilometres per hour (kmph), compared to the 225 kmph wind speed of the 1991 hurricane and 222 kmph wind force of the 1970 hurricane.
The names of previous cyclones could not be found in the records since the practice of naming them was not a standard back then. Met office sources said the names of futures cyclones that are likely to form over the Bay of Bengal and the Arabian Sea have already been fixed.
The name of the next possible cyclone that is to hit the region is 'Nargis' and the following one will be 'Abe'. The names were fixed earlier at a meeting of the World Meteorological Organisations (WMO), the sources said.
A responsible Met official however said Nargis, Abe, Khaimle, or Chapala are not necessarily going to hit Bangladesh, they might hit some other countries.
Weather experts of the Met office said Bangladesh faces cyclones and depressions every year during pre-monsoon and post monsoon seasons due to its geographical location. Sometimes more than one strong cyclone hit the country in a year, the met office records show. Interestingly many of the cyclones hit the country in post monsoon seasons, especially in the month of November.
According to the Met office records, on November 1, 1876 the 'Great Bakerganj Storm' hit Barisal region with a wind force of 220 kmph killing about two lakh people. The storm was considered 'a great human disaster', the records say adding that the tidal surge created by the storm was as high as 10 feet to 45 feet.
One of the senior weathermen of Bangladesh Meteorological Department, told the Daily Star that cyclones formed on the Bay of Bengal usually hit Bangladesh between April and May and between October and November, the pre-monsoon and post monsoon seasons respectively.
"The temperature of the sea surface needs to be more than 27 degrees celsius to form a cyclone. The higher the temperature, the higher the probability of a cyclone forming," said the divisional forecasting officer (DFO).
During monsoons wind streams over the Bay usually have greater force that is lacking in pre and post-monsoon wind streams. The monsoon wind stream does not usually allow any cyclonic formation to stay put at a point, forcing the storm to dissipate its force as the forceful wind stream moves it forward.
But in post and pre-monsoon seasons, cyclones formed on the Bay get opportunities to stay put at a point for a much longer period, gathering ferocity from evaporating water of the sea, turning into a 'low' first, and then a 'well marked low' and then a 'depression', which turns into a cyclone if it keeps gaining force.
When a cyclone gains wind speed of more than 118 kmph, weathermen call it a hurricane. According to the records of cyclones and tornadoes maintained by the Met office, a terrible cyclone packing a hurricane speed of 222 kmph ravaged the coastal districts of Barisal, Patuakhali, Noakhali, and Bhola, washing away a million people under 10 metre-high waves on Nov 12, 1970. It has since been remembered as the 'fearful November 12'.
In 1985, a cyclone ripping through Urir Char at 154 kmph with 15 feet high tidal waves, killed about 11,000 people.
On April 29, 1991 a 225 kmph cyclone swept over the coast of Chittagong with 25 feet high waves killing 1.4 lakh people.
Other cyclones hit Bangladesh in 1960, 1966, 1974, 1985, 1986, 1988, and in 1997. 'Ain-i-Akbari' and 'Riaz-us-Salatin' recorded the oldest account of a similarly violent cyclone in 1582. That cyclone razed the southern areas to the ground during a five-hour onslaught at a hurricane speed, failing to bring down to the ground only a few strongly founded temple buildings of that time.
According to the Met office sources, the names of the next possible cyclones to form on the Bay of Bengal or on the Arabian Sea are Nargis, Abe, Khaimale, Chapala, Megh, Vaali, Nada, Vardah, Sama, Mora, Nisha, Bijli, Aila, Phyan, Ward, Liala, Banda, Phet, etc.