The 1960 North Indian Ocean cyclone season featured two deadly tropical cyclones that killed approximately 60,000 people collectively in Bangladesh . On average, five storms form in the North Indian Ocean every season with dual peaks in activity during May and November.Cyclones that occurred between 45°E and 100°E were included in seasonal records by the IMD.
Fifteen depressions developed during the 1960 season, with five becoming cyclonic storms. The majority of the activity took place in the Bay of Bengal, where eleven systems formed; however, the season’s first storm formed over the Arabian Sea on May 10. The storm produced hurricane-force winds and attained a barometric air pressure of 974 mbar (hPa; 28.77 inHg). The deadliest and most intense cyclone of the season was Severe Cyclonic Storm Ten, which killed 14,174 in Bangladesh in early November. With peak winds estimated at 150 km/h (90 mph) and a pressure of 966.7 mbar (hPa; 28.55 inHg), it struck just three weeks after the previous system devastated the same area. The storm produced a 6.1 m (20 ft) storm tide that swept 16 km (10 mi) inland, submerging several small islands. The two storms left a combined 200,000–300,000 people homeless. These systems marked the start of an unusually active period of cyclones impacting East Pakistan, culminating ten years later with the 1970 Bhola cyclone
On May 25 of 1960,
an upper-level low pressure system developed over the northern Bay of Bengal. The following day, a surface low formed in association with this feature. By May 27, the low further consolidated into a depression while situated 285 km (175 mi) south of Kolkata, India.Tracking northward,it intensified into a deep depression before making landfall on the Sundarbans region of West Bengal—near the border of Bangladesh —early on May 28. Though it was classified a deep depression, stronger winds of up to 75 km/h (45 mph) were reported from Sagar Island. Based on measurements from nearby stations, it is estimated that the system attained a minimum pressure of 988 mb (hPa; 29.18 inHg) just as it moved ashore. Once inland, the system quickly weakened and accelerated northeastward.
The system produced torrential rains across eastern India and bangladesh. In Cherrapunji, 540 mm (21 in) of rain fell during a two-day span, while many other areas recorded over 100 mm (3.9 in). No rainfall data were available from West Bengal and Assam. Strong winds from the storm destroyed numerous homes in West Bengal, and at least seven people were killed
October 5 (Entered basin) – October 12
In late September, a tropical storm developed over the South China Sea. Striking Vietnam, the storm slowly moved over Indochina, ultimately crossing 100°E and entering the basin on October 5 while over Thailand. After crossing southern Burma,the low moved northwestward over the Bay of Bengal and reorganized. Following a report of 45 km/h (30 mph) winds from the S.S. Glenpark on October 8, the system was classified as a depression. Moving slowly northwestwards, the system further deepened into a cyclonic storm on October 9. Several ships in the path of the storm recorded gale-force winds, depicting its strengthening.
Early on October 10, it became a severe cyclonic storm and soon reached its peak intensity with winds of 110 km/h (70 mph). Its central pressure at this time was estimated to be 986 mbar (hPa; 29.12 inHg). The National Oceanic and Atmospheric Administration (NOAA) estimated that the storm attained one-minute sustained winds of 155 km/h (100 mph) Turning northeastward, the system made landfall between Barisal and Noakhali in bangladesh, with the eye passing directly over the islands of Bhola, Hatia, and Ramgati.Once onshore, the system quickly weakened and ultimately dissipated over Assam early on October 12.
Across coastal areas of Bangladesh, the storm wrought catastrophic damage. A 5.8 m 19 ft tidal surge washed over the islands of Hatia, Sandwip, Kutubdia. Communications across the region were crippled, and it took six days for word of the scale of damage to reach officials. Entire villages were reportedly wiped out by the storm.Approximately 35,000 homes were destroyed, most of which were thatched huts made of bamboo and mud. About 300 schools were also damaged. The worst damage took place on Ramgati Island where 3,500 people were killed. Roughly 95 percent of the island’s structure were destroyed, forcing residents to cling to trees for survival. Only two police officers survived and were able to inform government officials of the disaster.An estimated 6,000 people perished while another 100,000 were left homeless. Heavy rain accompanied the storm, with Cox’s Bazar reporting 180 mm (7.1 in). Relief efforts in the wake of the storm were hampered by the nation’s poor infrastructure and debris left behind.On October 18, members of the East Pakistani military were deployed to the hardest hit areas to provide stable communication and clean drinking water.
October 27 – November 1
|Peak intensity||150 km/h (90 mph) (3-min)|
On October 26, a trough formed over the south Andaman Sea and extended into the southern Bay of Bengal. By October 28, the system consolidated into a depression as it moved northwestward. Steadily intensifying, several ships encountered the storms increasing winds as it moved northward in the Bay. On October 30, it attained gale-force winds and further became a severe cyclonic storm early the next morning.
During the evening of October 31, the IST Barisal recorded winds of 130 km/h (80 mph), indicating that the system had acquired a core of hurricane-force winds. The maximum winds of this system is unknown, though reports indicated that winds peaked between 150 and 215 km/h (90 and 135 mph).NOAA estimated that the storm peaked with one-minute sustained winds of 195 km/h (120 mph) and a pressure of 966.7 mbar (hPa; 28.55 inHg).The storm soon made landfall with great intensity near Noakhali,bangladesh, just three weeks after the previous storm devastated the country . Once onshore, cold, dry air quickly wrapped around the backside of the cyclone. Within four hours of landfall, little rainfall was reported near the storm’s eye.The cyclone rapidly weakened and dissipated the following day over the Lushai Hills.
Striking Bangladesh as a powerful storm, the system produced a storm tide of 6.1 m (20 ft) that moved 16 km (10 mi) inland, devastating many communities. A storm surge of 6.7 m (22 ft) was measured in Halishahar. In addition to the surge, there was a series of tidal waves that followed the storm, causing additional damage. Offshore, these waves were estimated at 12.2 m (40 ft); though they significantly decreased before impacting land.
Chittagong and surrounding communities were regarded as the hardest hit, with most being submerged in 3 m (10 ft) of water. The city’s port was largely destroyed, with almost every vessel washed ashore. Some were found 16 km (10 mi) away and one even at another port. The storm’s intense winds, estimated as high as 240 km/h (150 mph) on Sandwip Island, leveled buildings and scattered debris over large distances. Crops were flattened by the storm and in some instances had been “burnt” by the sheer force of the wind. A total of 14,174 people perished in the storm while another 200,000 were left homeless. Following the mass casualties from the two storms, the Government of Pakistan requested the assistance of former National Hurricane Center director, Gordon E. Dunn, to improve the warning system