Bangladesh sees record days of heatwave in 76 years

Abu Sayeed, a laundry owner at Monipuripara in Dhaka, was taking a rest outside of his shop though a large heap of clothing was awaiting his attention. Chatting with him on Thursday evening revealed that his assistant left work for his village home two days ago without telling him, being unable to iron in this extreme hot weather .

“I can’t take this hot weather anymore. Though there is not that much power outage and the fan is also working properly, it is not enough in this weather. Work is so exhausting! When will there be rain?” said Abu Sayeed.

The whole country has been waiting for the rain.

Meteorologists say that in April the country saw the highest number of consecutive days of heatwave in the last 76 years. The heatwave lasted for 16 consecutive days last year. This year the heatwave started from 1 April and has been continuing as of 26 April.

The Bangladesh Meteorological Department has specific data of heatwave from 1981. An analysis of that data reveals that Rajshahi experienced 20 days of heatwave in 2010. But that was in spells. But this year, the country has been seeing heatwaves for 26 days. The weather will remain the same for a few more days, says the forecast.

Meteorologist Muhammad Abul Kalam has been conducting research on heatwave for a long time. He told Prothom Alo on Thursday, “I’ve analysed data available from 1948 but have not found any record of heatwave for such a long time at a stretch. It can be said that the record of 76 years has broken.”

Alongside the heatwave for the highest number of consecutive days, 75 per cent of the area of the country has been experiencing the severe heat, which is another record, said meteorologist Md Umar Faruk.

In the last 43 years, Jashore district saw the highest number of days of heatwave. The district was followed by Chuadanga and Dhaka.

Speaking about the overall situation, former professor at the Bangladesh University of Engineering and Technology (BUET) Ainun Nishat told Prothom Alo Friday that uncertainty has become the main feature of weather due to climate change. The rhythm of nature has already been damaged or about to be damaged. This time the heat is exhausting but later we might see the weather has become cooler. Facing this extreme weather has become a great challenge.

Meteorologists and experts identified four reasons for such extreme weather. Those are - the subcontinent’s high heat zone, decreased amount of orographic rainfall, active El Nino and the decreased amount of thunderclouds.

Speaking to Prothom Alo, BUET’s Institute of Water and Flood Management (IWFM) director professor AKM Saiful Islam, who is also involved with the UN’s  Intergovernmental Panel on Climate Change (IPCC), globally the temperature has increased by 1.3 degrees Celsius. This has affected Bangladesh too.

This heat has dispersed the whole subcontinent, think the experts. They said a high heat zone has appeared in the area. As a result, the temperature in India, Pakistan and Bangladesh is more than the normal trend, said Saiful Islam.

According to the meteorologists, decreased orographic rainfall is also a reason for severe hot weather this year. Orographic rainfall is rain produced when the mountains act as barriers to airflow, forcing the air to rise and the moist air moving upslope cools down by producing clouds and precipitation.

This is why the windward side of hills experience more rain than the leeward side, said meteorologist Muhammad Abul Kalam Mullick.

He further said such rainfall is seen in India’s Assam, Meghalaya and Paschimghat Hills, Bangladesh’s Chattogram, and Myanmar’s Arakan hills. Sylhet region of Bangladesh also experiences such rain which is very low this year. This is why the weather is so hot, he argued.

El Nino is a global climate phenomenon that emerges from variations in winds and sea surface temperatures over the tropical Pacific Ocean. The opposite effect is la nina. Meteorologists said about an active El Nino in September last year and warned that there will be intensified heatwaves across the globe this year. The Australian Bureau of Meteorology in its report on 16 April said that El Nino has ended.

Speaking about this, meteorologist Hafizur Rahman told Prothom Alo that though the El Nino has ended, its effect is still active. That is why the heatwaves have increased.

This April, the country saw only one nor’wester which was seven last year. Thunderclouds form nor’wester and rain and squally wind. Bangladesh will have to wait for the formation of thunderclouds in India’s Bihar, Odisha and West Bengal which seems far-flung right now.

BUET’s Institute of Water and Flood Management (IWFM) director Professor AKM Saiful Islam mentioned the arrival of La Nina after the end of El Nino.

According to him, La Nina becoming active means there would be more rains in the coming rainy season. The reason is heat accumulated in the earth and in the seas will cause more vapour, which will cause more rainfall.

The Indian meteorological department on 15 April forecast that there would be more rainfall than normal in the coming monsoon period.

Speaking about this, meteorologist Shaheenul Islam said, “Rain from locally formed clouds cannot lessen the ongoing severe heat. We will have to wait for storms and thunderclouds. Only storms induced by thunderclouds could lessen the ongoing heatwaves sweeping over the central region including Dhaka, Khulna and Rajshahi.”

* The report, originally published in the print and online editions of Prothom Alo, has been rewritten for English edition by Shameem Reza