IMD sounds heatwave alarm in north, east over next two weeks
Heatwave to severe heatwave conditions are likely to set in over several parts of northwest and east India by the end of April and extend into early May, the India Meteorological Department (IMD) said on Sunday.
IMD’s extended range forecast for April 22-28 and April 29-May 5 suggest maximum temperatures are likely to be significantly above normal (3°C- 6°C above normal) over many parts of the country during the week starting on April 29.
Parts of east India, including Odisha, Jharkhand, Bihar etc, are likely to be significantly impacted by heat stress, parts of northwest India are likely to also report extremely high temperatures, the forecast stated.
Overall, rainfall activity is likely to be normal to above normal over extreme south Peninsular India, covering mainly Kerala and coastal Karnataka, northeast India, Kashmir; below normal rainfall is expected over the plains in the northwest -- Himachal Pradesh and Uttarakhand -- and near normal rainfall is projected over rest of the country, the forecast said.
“Our models are showing that Odisha, Jharkhand, east Uttar Pradesh, Chhattisgarh, Bihar will be badly impacted by the heat wave. I would say that east India will be more affected this time. There will be above normal temperatures and heatwaves over northwest India also during the next two weeks. But at least due to approaching western disturbances, the heatwaves are not likely to continue. The ‘normals’ are increasing so the impact of heat waves will be more intense. But in the east, it’s the combination of severe heat and humidity that will affect people,” explained RK Jenamani, senior scientist, national weather forecasting centre at IMD.
“There is a feeble western disturbance approaching around April 28 but after it moves away, we do not expect any systems that can help relieve heat wave conditions. So maximum temperatures can go upto 46°C over some parts of northwest India and upto 48°C over regions like Barmer, Churu, Daltonganj, Vidarbha, parts of south Madhya Pradesh etc where temperatures had reached around 48°C earlier in April during the prolonged heat wave spell,” explained Mahesh Palawat, vice president, climate change and meteorology at Skymet Weather.
“The anti-cyclone could shift to south Rajasthan, leading to incursion of very hot winds,” he added.
“Warning for heat waves! The Extended Range Forecasts of @Indiametdept suggests suppressed rainfall activity over most of the country except Kerala & TN during next 4 weeks Consequently, temps are expected to rise leading to heat waves over northern parts & east coast,” tweeted M Rajeevan, former secretary, ministry of earth sciences on April 21.
“Peak Summer level #Heatwave Outbreak: Anti cyclonic circulation wind pattern to appear over #India by fag end of April - May first week. Resulting in Severe Heatwave over North & Central states, Max might reach 46-48°c in #Rajasthan, S #UttarPradesh, Up to 44-46°c in #Delhi NCR,” tweeted Navdeep Dahiya, founder of Live Weather of India, a private forecasting company on Saturday.
According to the IMD, there is a 29% rain deficiency so far over the country during the pre-monsoon season that started on March 1 with 87% deficiency over northwest India; 70% over central India; 32% excess over peninsular India and 10% excess over east and northeast India.
The projection states that a feeble western disturbance is likely to affect the Western Himalayan region from the night of April 28 and likely to bring isolated rainfall and thunderstorm activity over the higher ridges of Kashmir-Ladakh-Gilgit-Baltistan-Muzaffarabad, Himachal Pradesh and Uttarakhand during April 28-30. Another western disturbance is very likely to affect Western Himalayan Region and adjoining plains of India from May 3, it stated.
There is likely to be a gradual rise in maximum temperatures by 2°C-4°C from Monday, IMD warned. There is also likely to be a rise in maximum temperatures by 2°C-3°C over Madhya Pradesh over the next three days and no large change thereafter.
No large change in maximum temperatures over Gujarat state and Maharashtra during the next 2 days and a rise by about 2°C thereafter. A gradual rise in maximum temperatures by 2°C-3°C is also likely over east India during the next 3 days.
Heat wave conditions are very likely to prevail in isolated pockets over Gujarat state during next 5 days; over Bihar during April 24 to 26; over Madhya Maharashtra, Jharkhand, Odisha, Gangetic West Bengal during April 25 to 28; over Rajasthan, south Uttar Pradesh, Madhya Pradesh, Vidarbha during April 26 to 28 and over Punjab and south Haryana on April 27 and 28.
No significant change in maximum temperatures is projected over the rest of the country.
Severe heat wave conditions were observed in isolated pockets over Saurashtra and Kutch and heat wave conditions in isolated pockets over Gujarat region. Maximum temperatures (as on April 23) were 40°C-42°C in many parts of West Rajasthan, East Uttar Pradesh, Bihar, Gujarat, Vidarbha, Marathwada and Madhya Pradesh; in some parts of Haryana-Delhi, Madhya Maharashtra, Jharkhand and in isolated pockets over East Rajasthan, Telangana, Rayalaseema, Odisha and Gangetic West Bengal.
According to IMD, a heat wave is recorded in areas where the normal maximum temperatures are in excess of 40°C when the actual maximum temperature is between 4°C -5°C higher. For regions where the normal maximum temperatures are 40°C or lower, a heat wave is declared when the actual maximum temperature is 5°C-6 °C higher. A heat wave is declared only when the maximum temperature of a station reaches at least 40°C for the plains and at least 30° C in the hills. Heat waves can also be declared when the actual maximum temperature remains above 45°C or more for a day irrespective of normal maximum temperature.