A man raises a storm danger signal flag ahead of Cyclone Mocha's landfall in Bangladesh on May 13, 2023. The South Asian nation lacks a warning mechanism for pre-monsoon storms called nor’westers. (Photo: AFP)
At least 13 people have been killed and several hundred families lost their houses in a pre-monsoon storm — known locally as a nor’wester — that hit Bangladesh without warning on April 7.
Seven southern and southwestern districts of the South Asian nation were badly affected by the weather phenomenon, that generally blows over Bangladesh in March-May from a northwesterly direction.
An 80-year-old resident of North Ranipur village in Shariktala union, was reportedly blown off his feet and later found dead in a canal.
The department of disaster management recorded 13 deaths mainly in Pirojpur, Patuakhali, Jhalkathi, Bhola, Khulna, Netrokona and Bagerhat districts.
In Bhola, over 7,000 people were affected and 600 houses damaged on Manpura Island.
Many deaths were a result of lightning strikes and damage to dwelling places. The dead were mostly farmers who kept on working in the open, unaware a storm was approaching.
An effective early warning system could have saved their lives, said Meherun Nesa, coordinator of Disaster Forum, a Dhaka-based organization that keeps tabs on nor’westers.
Nor'westers occur when dry westerlies meet warm and moisture-prone southerlies in the Bay of Bengal. The wind blows in a northwesterly direction when the land temperature increases. Nor’westers disappear with the onset of the monsoon in June.
Accompanied by lightning and hail, the latest nor'wester, locally known as Kalbaishakhi, lasted half an hour and uprooted thousands of trees.
On March 31, a devastating nor’wester saw in a hailstorm which people in Sylhet division described as unprecedented due to the size of hail stones.
Disaster Forum said that storm injured nearly 100 people and damaged many houses and vehicles.
On March 24, strong winds, accompanied by hailstorms, swept four divisions, including Dhaka, in the early hours. The meteorological department recorded the wind blowing up to 92 km per hour in the national capital.
Due to the prevalence of nor’westers in March, the average temperature dropped 3C below the normal level, according to the Bangladesh Meteorological Department.
Abdul Mannan, a former scientist with the state-run agency, said that there has been a constant moisture incursion from the Bay of Bengal, triggered by an unusual weather system.
“This phenomenon has become common nowadays due to climate change,” said Mannan, who is now associated with the Bangladesh Agricultural Research Council as climate coordinator.
In March, at least 10 people were killed by lightning in Bangladesh.
Lightning claimed 133 lives, including 23 children, in the pre-monsoon season last year, Disaster Forum said.
The country lacks a mechanism to give adequate nor’wester warnings.
Weathermen said that it is possible to exactly determine the place and time of a nor’wester half an hour before it strikes.
But there is no mechanism to inform people, they added.
The meteorological department issues a generalized weather forecast daily; often featuring a sweeping warning that “lightning might occur in many places.”
Over the last 14 years, since the nation began keeping tabs on the death toll from natural calamities, Disaster Forum recorded 3,746 fatalities, mostly farmers and 633 children, due to the pre-monsoon storms. Since 2020, Bangladesh has seen more than 300 deaths.
