Nearly a week on from the temperature peaks of the heatwave over northwest India, the subject has quietly dropped out of the media discourse in India. However, this shouldn’t mean that the heatwave itself is gone. On 7 May, the Indian Meteorological Department (IMD), forecast heatwave conditions over much of northwest and central India. It’s expected to set in today and continue for the next three days.
This means maximum temperatures in the range of 42-44 degrees Celsius in the region. Areas affected will be the eastern and western parts of Rajasthan, south Haryana, west Madhya Pradesh, Punjab and Jammu. On Saturday, Barmer in Rajasthan experienced a maximum temperature of 45 degree Celsius.
♦Heat Wave conditions in isolated pockets likely over Vidarbha during 07th-11th and West Rajasthan during 08th-11th; south Haryana & East Rajasthan during 09th -11th; West Madhya Pradesh on 08th & 09th and south Punjab & Jammu Division on 10th & 11th May, 2022. pic.twitter.com/X5mbtiJgOR— India Meteorological Department (@Indiametdept) May 7, 2022
Meanwhile, it’s cyclone season, and quite predictably, a cyclone—Cyclone Asani—is brewing in the Bay of Bengal. According to the IMD, Asanti is currently near the Andaman Islands is going to intensify into a severe cyclonic storm (SCS) over the next 24 hours. It will move towards the east coast (northern Andhra Pradesh-southern Odisha), before weakening into a deep depression. According to present estimates, it may not make landfall, nor intensify further than an SCS.
Cyclonic storms feed off the heat generated by high sea surface temperatures (SST), and with both the Bay of Bengal and the Arabian Sea warming considerably due to climate change, we’ve seen big cyclones make landfall every year for the past few years. This year, the SST over the Bay of Bengal remains higher than normal, at about 30-31 degree Celsius. However, according to IMD’s observations, the ocean heat content is currently higher over the Andaman Sea, south and central Bay of Bengal than in northwest Bay of Bengal. This would explain the forecast of Cyclone Asani first intensifying, and ultimately weakening the closer it gets towards the Odisha coast. But it would be prudent to keep an eye on the storm.
Deep Depression over intensified into a cyclonic storm ‘Asani’ about380 km west of Port Blair (Andaman Islands).To move northwestwards and intensify further into a Severe Cyclonic Storm over east central Bay of Bengal during next 24 hours pic.twitter.com/3AkJAtHIxw— India Meteorological Department (@Indiametdept) May 8, 2022
Meanwhile, further analysis of the massive heatwave of the past month reveals the extent to which climate change is impacting normal weather patterns. Winter and early spring storms over North-West India, commonly known as Western Disturbances (WDs), are responsible for much precipitation over the region—ranging from snowfall in the Karakoram and the Himalaya to rains over the plains—and play an important role in suppressing heatwave conditions before the onset of the monsoon. However, they may be weakening. This year, WDs were fewer in March and April, while also being less strong than usual.
This resulted in a prolonged lack of rainfall over the plains, which then failed to suppress the heating effects of weather phenomena known as anti-cyclones over northern India. “The anticyclone sent warm winds from north-west to central and western India for longer duration, causing as well as intensifying the heat waves. In absence of rains, the desert region was already witnessing high temperatures. Not to forget, that winds have been warmer than earlier on account of global warming, hence heat waves are more intense now. This makes Western Disturbances even of more importance for Northwest India, as only they can force anticyclone to dissipate or move further,” said Mahesh Palawat, VP- Meteorology and Climate Change, Skymet Weather in a statement.