ISRO INSAT shows active thunderstorms and strong convection over eastern India, but reserve cloud cover over central and western India.
Nearly two weeks after the onset of the southwest monsoon in Kerala on June 4, several parts of India are witnessing light to heavy rains. While parts of northwestern, eastern and southern India received rain showers over the past week, the monsoon does not seem to have had an impact on the western parts yet.
This comes even as a review of the crop situation tabled before the Maharashtra Cabinet showed that the state received only 26 per cent of the usual rainfall in the first half of June, news agency PTI reported. Moreover, according to India Meteorological Department Nowcast, a large part of the country on Wednesday had no weather alerts or warning and remains green, indicating no rainfall is expected in these parts at the moment.
While these signs raise concerns, data received for weather activity and cloud cover over India from three different satellites indicate a worrying situation.
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Uneven distribution and dry air over the parts: what do the data from satellites say?
Satellite images from Meteosat (IODC), operated by Eumetsat, show dense cloud masses over the northern Bay of Bengal, indicating that the monsoon is functioning relatively normally in states such as Odisha, West Bengal, Jharkhand and Bihar, with northeastern India also receiving showers.
However, Meteosat images show discontinuities in the Arabian Sea branch of the southwest monsoon, meaning that western India does not receive continuous rain, with heavy rainfall falling in bursts rather than continuous episodes. The data also shows dark or cloud-free gaps in interior regions, a week after the IMD indicated slow progress of the monsoon.
The reason for this can be gauged by looking at satellite images from the US National Oceanic and Atmospheric Administration (NOAA) satellites. These show that the intertropical convergence zone (ITCZ), which moves north by mid-June and pulls moisture into India, is moving with less force. This prevents the monsoon from accelerating in some parts. There are also signs of El Niño conditions developing, which could cause a reduction in convection over India, leading to longer dry spells and uneven rainfall.
ISRO INSAT also shows active thunderstorms and strong convection over eastern India, but shows reserve cloud cover over central and western India, including Madhya Pradesh, Vidarbha, Gujarat and Rajasthan.
What about El Nino conditions?
The IMD, even before the onset of the monsoon, had predicted the monsoon to be weaker, anticipating it to reach 90% of the long period average (LPA). The long period average (LPA), based on data for the period 1971-2020, is 87 cm.
As El Niño conditions associated with a weak monsoon develop in India, the impact is likely to be “relatively severe” in 12 states, including Uttar Pradesh and Tamil Nadu, according to the agriculture ministry.
“In 9 to 10 states where the impact of El Niño may be relatively higher, coordinated meetings should be organized with district magistrates, agriculture departments, Krishi Vigyan Kendras (KVKs) and other extension systems in the identified areas,” Union Agriculture Minister Shivraj Singh Chouhan said, according to news agency PTI.
