February 9, 2025
25 C
Dhaka

Winter to intensify in Bangladesh this season

Experts have warned that at least twelve cold waves and hailstorms may occur in the three months from December to February

After tackling severe floods, cyclones and heat waves, Bangladesh will now have to deal with the coldest winter this season.

Experts have warned that at least twelve cold waves and hailstorms may occur in the three months from December to February, adding that the chilly weather could trigger a volley of cold-related diseases, and have a devastating effect on crops.

They have conveyed cautionary messages to raise awareness towards cold-related diseases, and issued guidelines for people working outside.

Bangladesh Meteorological Department (BMD) meteorologist Afroza Sultana said, “The winter will be significantly chillier this season compared to the last one. Bangladesh witnessed more rainfall in the August-September period this year.

“The heavy rainfall will result in more fog. There will also be more dust particles in the air. Due to these factors, winter will be even colder this season.”

Echoing the same, BMD meteorologist Dr Md Bazlur Rashid said, “This year, winter may become more severe than last year. The cold was not that intense last December, but this year, the country witnessed a mild cold wave.

A low-pressure formed in the Bay of Bengal on December 19, and it is expected to cause heavy rainfall. “After two days of rain on December 21-22, the cold wave will resume.” Climate induced unpredictable weather is taking a heavy toll on people, especially on the marginalized and women population.

In 2024, Bangladesh recorded at least thirty-five heat strokes, while temperature reached 43.8°C. Government records show fourteen people died in heatstroke this year. Due to the sweltering heat, educational institutions across Bangladesh had to be closed several times in 2024.

The Climate Watch Graph
The Climate Watch Graph

Besides, almost half of Bangladesh (25 out of sixty-four districts) became submerged in water for 57 days due to severe floods. This South Asian country was affected by nine floods and two cyclones in 2024, leading to the deaths of at least seventy-one people.

How severe will the winter be?

The BMD had given a three-month long-term forecast at the beginning of this December on the severity of winter.

As part of this forecast, BMD Director Md Momenul Islam said, “At least 12 cold waves and hailstorms may occur in these three months from December to February. A minimum of three and maximum of eight mild to moderate cold waves may occur during this period.

“Apart from this, three to four severe cold waves may occur in the northwestern, northeastern, and central regions of the country. Rainfall will be normal during this period.”

Between December 14 and 17, the Mymensingh region witnessed dense fog since midnight. Blankets of thick fog covered the region from 10 am to 10:30 am.

Low pressure in Bay of Bengal

The low pressure which was formed in the Bay of Bengal on December 19, and it is currently located in the sea in a severe form.

The BMD predicted that the low may develop into a depression, which in turn would trigger light to moderate rains in Dhaka, Chattogram, Khulna, Barisal, and Rajshahi divisions on Saturday, and Khulna, Barisal and Chattogram divisions on Sunday.

On the issue, meteorologist Dr Muhammad Abul Kalam Mallik said, “After the rainfall, the temperature will gradually start to drop across the country. Chilly weather will gradually set in throughout different divisions and districts, including in the northern part of Bangladesh.

“The difference in the maximum and minimum temperatures will gradually decrease. The northern and western wind speed will increase. The southern shifting of the jet stream in the upper sky moving southwards and downward may further intensify the freezing weather.”

This will lead to chillier weather from December 23 or Monday, he added.

6 reasons behind intensifying winter

Discussing the six key reasons behind chillier weather this season, Dr Mallik said first, the southward expansion and downward movement of extremely chilly air, with higher speed in the upper sky, can intensify the winter.

Second, dense fog from midnight to morning would prevent sunlight from penetrating through the fog. Due to less sunlight, the rate of surface heating will decrease.

Third, the freezing air coming from the northwest, for example from the foothills of the Himalayas, will mix with the relatively warm air of Bangladesh and increase the feeling of chill.

Fourth, the Indian high-pressure zone has spread to Delhi, Uttar Pradesh, Madhya Pradesh, Bihar, and West Bengal. It has gradually developed a tendency to spread to Bangladesh. It will spread to the western part of Bangladesh by Monday (December 23).

If this high-pressure zone spreads to the central part of the country, it will increase the feeling of winter chill. Due to the low water vapor content in the air of the high-pressure zone, it will be colder. So, it will most certainly increase the intensity of winter in Bangladesh.

Fifth, the availability of sunlight will decrease during this time. Sixth, there will be less water vapor in the air. The chilly weather will intensify due to a combination of these key factors.

Dr Mallik further pointed out that the temperature will decrease slightly due to rain in the southern parts of Bangladesh including Rajshahi and Dhaka divisions from Friday and Saturday midnights.

The temperature will continue to drop in December, but there is no danger of moderate (6-8 degrees Celsius) or severe (4-6 degrees Celsius) cold waves this month.

However, temperature in some areas, especially in Panchagarh, Naogaon, Lalmonirhat, Thakurgaon, Satkhira, Ishwardi in Pabna, Sreemangal in Moulvibazar, Gopalganj, Jessore, may drop below 8-10 degrees Celsius. Due to this, a mild cold wave (8-10 degrees Celsius) may start.

January would be the coldest month this winter season, and there is a risk of moderate to severe cold wave this month. A mild cold wave has already swept through several districts from December 13-16.

Highest-lowest temp difference 12-14 degrees

Noting that the difference between the highest and lowest temperatures plays a key role in increasing the feeling of wintry weather, Dr Mallik said, “Currently, the highest and lowest temperatures are fluctuating between 12-14 degrees Celsius.

“When this difference starts dipping below 10 degrees Celsius, the intensity of cold will begin to increase. When this difference comes within the 5-degree Celsius range, Bangladesh will witness bone-chilling cold. This will be the case in January.”

Meanwhile on Friday, according to the BMD, the difference between the highest and lowest temperatures in Dhaka was 11 degrees Celsius and the lowest was 10.5 degrees Celsius in Narayanganj. The difference between the highest and lowest in Rajshahi was 13.4 degrees Celsius.

There was a 16.8-degree Celsius difference between the highest and lowest temperature in Rangpur’s Panchagarh, and this difference was 14.6 degrees Celsius in Netrokona. This figure was 13 degrees Celsius in Bandarban, 10.4 degrees Celsius in Mongla, and 12.9 degrees Celsius in Patuakhali.

Apart from that, twenty out of 51 weather stations in the country recorded the temperature at less than 13 degrees Celsius last Friday.

Effects of La Nina & IOD

La Nina is a natural phenomenon that occurs when the ocean surface temperatures in the central and east-central equatorial Pacific cool below normal. This event is the cold phase of the El Niño/Southern Oscillation (ENSO) cycle.

Meanwhile, IOD stands for Indian Ocean Dipole, a climate pattern that affects the Indian Ocean and the weather in Australia.

Mentioning that both these factors have an impact on the winter season of Bangladesh, Dr Mallik said, “The condition of La Nina is normal from October to December. There is an indicator that the feeling of winter may increase in Bangladesh.

“Apart from that, there is another indicator called IOD or Indian Ocean Dipole. The phase of this indicator is in the negative phase. And if it is negative, the temperature in Australia and its surroundings increases, but it remains low in the Arabian Sea. Therefore, the temperature in the Indian subcontinent or Bangladesh will decrease.”

He added that the intensity of winter will increase in Bangladesh – especially from January – due to the existence of La Nina, negative conditions of IOD and six other factors.

Rainfall: Beneficial or harmful?

Terming the rainfall forecast as positive, meteorologist AKM Nazmul Haque said there is no chance of harm because of the drizzle. It may even be beneficial. However, the low pressure in the sea could develop into depression.

Currently, the low pressure is in the southwest Bay of Bengal and its nearby areas. It may move slightly further north and condense. It has already extended to the north Bay of Bengal.

Meanwhile, meteorologist Dr Md Bazlur Rashid said, “Whether the rain is beneficial or harmful depends on the amount. If there is a lot of rain, it can cause damage. Whereas light rain can be beneficial.

“However, the forecast does not predict heavy rain. Clouds have formed the southern part of the country, namely Khulna, after Friday evening.”

Meanwhile, meteorologist Md Tariful Newaz Kabir said, “Light to moderate rain is likely to occur in some places in Khulna and Barisal divisions on Saturday, and in a couple of places in Rajshahi, Dhaka and Chattogram divisions.

“Apart from this, the weather may remain mainly dry, with partly cloudy skies elsewhere in the country. Night temperatures may increase by 1-2 degrees Celsius across the country, while day temperatures may decrease slightly.”

Meanwhile, light rain is likely to occur in a couple of places in Khulna, Barisal and Chattogram divisions on Sunday. The weather may remain mainly dry with partly cloudy skies elsewhere in the country.

Night temperatures may decrease slightly across the country and day temperatures may remain almost unchanged. Light to moderate fog may fall in some places in the northern part of the country from late night to morning. The temperature will continue to drop for the next 5 days.

On December 20, the lowest temperature in Bangladesh was 10.7 degrees Celsius in Tetulia of Panchagarh, and the highest was 31 degrees Celsius in Bandarban.

Impacts on agriculture

Farmers are now sowing seeds for the Boro season, and potato planting continues. Early varieties of potatoes are being harvested in some places.

Discussing the potential impact of a chillier winter on the country’s agriculture, Bangladesh Rice Research Institute Director General (routine duty) Dr Mohammad Khalequzzaman said, “If the intensity of winter gets high, rice seedlings will not grow.

“The seedlings could die, and other vegetables could also get damaged. Especially, if there is a lot of fog, the potato plant yields will be impacted severely. So, farmers should shake the dew off the rice seedlings.”

Expert guidelines for working outside

Renowned physician and former Dean of the Department of Medicine of Bangabandhu Sheikh Mujib Medical University Dr ABM Abdullah advised everyone to cover their heads and ears while working outdoors or in open areas during winter.

People should cover their heads and ears while working outside their home – Dr ABM Abdullah, Physician, Bangabandhu Sheikh Mujib Medical University

He further recommended, “When the temperature decreases naturally, the human body’s immunity also decreases. This causes diseases such as respiratory illnesses, pneumonia, and chest diseases.

“Scabies and skin disease cases also go up. Diseases are increasing among children and the elderly. If a person must work outside in this severe winter, they should cover their head and ears as much as possible.”

People should also avoid staying in water for extended periods of time, and warm up their body after in between work sessions, he added.

Latest News

Coastal climate adaptation fair held in Bangladesh

Local innovations that attracted attention included "Rozela Tea" and...

How can Nepal reduce forest fire risks?

Nepal loses a great deal each year to forest...

Youth must lead the charge in climate action – VC SUST

Acting Vice-Chancellor of Shahjalal University of Science and Technology...

Concrete blocks offer hope amid Bangladesh’s Brick kilns pollution

Narayanganj – a district spanning 683 square kilometers with...
spot_img
spot_img

Editor's Choice

COP29: A step forward or a missed opportunity?

The UN climate summit ended on Sunday with a...

Nepal’s First GCF Project shining but hit by long processes

The family of Lalit Thapa from Dudhauli Municipality-3, Upper...

Urban flooding rises in Dili due to high rainfall intensity

Over the past 20 years, Timor-Leste has been experiencing...
spot_img

Related Articles

Popular Topics