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1970 Bhola cyclone

North Indian Ocean cyclone

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This ITOS 1 weather satellite image of the November 12, 1970 Bay of Bengal Tropical Cyclone was taken at 0956 UTC
NOAA · Public domain

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Through Bangladesh, Pascal (unit) and Tide

The cyclone formed over the central Bay of Bengal on 8 November and travelled northward, intensifying as it did so. It reached its peak with winds of 185 km/h (115 mph) on 10 November, and made landfall on the coast of East Pakistan on the following afternoon. The storm surge devastated many of the offshore islands, wiping out villages and destroying crops throughout the region. In the most severely affected upazila Tazumuddin, over 45% of the population of 167,000 were killed by the storm.

The Pakistani government, led by junta leader General Yahya Khan, was criticized for its delayed handling of relief operations following the storm, both by local political leaders in East Pakistan and by the international media. The poor and discriminatory response from the West Pakistan government led to the increasingly widespread disillusionment from the East Pakistani people, allowing the opposition Awami League to gain a landslide victory in the province during the election that took place a month later as well as the Bangladesh Liberation War seven months later.


Meteorological history

On 1 November, Tropical Storm Nora developed over the South China Sea, in the West Pacific Ocean. The system lasted for four days before degenerating into a remnant low over the Gulf of Thailand on 4 November, and subsequently moved west over the Malay Peninsula the next day. The remnants of this system contributed to the development of a new depression in the central Bay of Bengal on the morning of 8 November. The depression intensified as it moved slowly northward, and the India Meteorological Department upgraded it to a cyclonic storm the next day. No country in the region had ever named tropical cyclones during this time, so no new identity was given. The storm became nearly stationary that evening near 14°30′N 87°00′E / 14.5°N 87°E, but began to accelerate toward the north on 10 November.

The storm further intensified into a severe cyclonic storm on 11 November and began to turn towards the northeast as it approached the head of the bay. It developed a clear eye and reached its peak intensity later that day, with three-minute sustained winds of 185 km/h (115 mph), one-minute sustained winds of 240 km/h (150 mph), and a central pressure of 960 hPa. The cyclone made landfall on the East Pakistan coastline during the evening of 12 November, around the same time as the local high tide. Once over land, the system began to weaken; the storm degraded to a cyclonic storm on 13 November, when it was about 100 km (62 mi) south-southeast of Agartala. The storm then rapidly weakened into a remnant low over southern Assam that evening.

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