E-Paper
Monsoon unlikely to progress for nearly two weeks: IMD
India receives about 70% of its annual rain during the four-month monsoon that is crucial for rice, soybean, and cotton cultivation. As much as 60% of the sown area does not have access to irrigation in India, where over 150 million farmers and nearly half of the population are dependent on a farm-based income.
The monsoon is unlikely to progress to Delhi, Chandigarh, Haryana, remaining parts of Rajasthan, west Uttar Pradesh, and Punjab for nearly two weeks and is also likely to enter a “break spell” from June 29 onwards, the India Meteorological Department (IMD) said on Saturday. Heavy rain will be confined to northeast India while rainfall will be subdued in the rest of the country at least till around July 5, it added.
“Models suggest monsoon entering into a break spell from July 29. Heavy rains to be confined mainly over northeast India at least till July 5 with suppressed rainfall over rest of India. Active-break spells are part of monsoon dynamics and decides quantum of seasonal rainfall,” tweeted M Rajeevan, secretary, ministry of earth sciences. He added break spells normally last for a week. But in some years, they have lasted over 10 days. Longer breaks can affect agriculture.
India receives about 70% of its annual rain during the four-month monsoon that is crucial for rice, soybean, and cotton cultivation. As much as 60% of the sown area does not have access to irrigation in India, where over 150 million farmers and nearly half of the population are dependent on a farm-based income.
From June 1 to June 26, the country recorded 20% excess rain. There was 43% excess rain in northwest India, 36% in central India, 3% in the east and northeast India, and 7% in the south peninsula. Out of 36 subdivisions, seven recorded large excess rain (60% or more above normal), 14 recorded excess rain (20 to 59% excess), seven recorded normal rain (-19% to 19%) and eight recorded deficient rain (-20% to -59%).
The northern limit of the monsoon continues to pass through Barmer, Bhilwara, Dholpur, Aligarh, Meerut, Ambala, and Amritsar. It has been in the same position for a week.
IMD, in its bulletin, on Saturday cited the prevailing meteorological conditions, atmospheric features, and the forecast wind pattern by dynamical models and added they suggest that no favourable conditions are likely to develop for further advance of southwest monsoon into remaining parts of Rajasthan, west Uttar Pradesh, Haryana, Chandigarh, Delhi and Punjab over the next seven days.
It added subdued rainfall activity is very likely in the northwest, central, and western parts of peninsular India during the next five days. A subdued rainfall phase will merge into the break monsoon phase likely to begin on June 29.
Under the influence of strong moist south-westerly winds, fairly widespread to widespread rainfall is very likely in West Bengal, Sikkim, and north-eastern states during the next five days.
Subsequently, moist easterly winds are likely to pick up in strength, causing enhanced rainfall activity all along the foothill regions of north Bihar, north Uttar Pradesh, Uttarakhand, and Himachal Pradesh around July 1 and 2. This will lead to increased inflow into the rivers which originate from these regions, IMD said.
O P Sreejith, who heads IMD Pune’s Climate Monitoring and Prediction Group said normally break monsoon phase happens when the monsoon has already covered the entire country. “The monsoon trough moves to the foothills and wind flow is mostly westerly. There is little contribution from the Bay of Bengal and hence little convective activity. During break monsoon phases, rains are limited to northeast India. But this time the trough is not near the Himalayan foothills, but the monsoon flow itself has weakened.”
He said up to July first week, there are no indications of monsoon revival. “The cross-equatorial flow has weakened, and the pressure gradient is less. Normally monsoon flow moves from high-pressure areas to low-pressure areas. The monsoon current itself has weakened. Monsoon onset is unlikely over remaining parts of the country till monsoon revives. It may revive when a low-pressure system forms over the Bay of Bengal. We have no information on when a low-pressure area is likely to form.”
K Jenamani, senior scientist, National Weather Forecasting Centre, IMD, said monsoon will not cover the remaining parts of the country until conditions become favourable. “Large scale features are not supporting monsoon progress and activity.” He said cross-equatorial flow has weakened and there is no convection over the Arabian Sea and Bay of Bengal and wind is also unfavourable. Jenamani said mid-latitude westerlies have strengthened and the Madden Julian Oscillation (MJO) is also not over the Indo-Pacific region.
MJO location and amplitude strongly modulate the intensity of tropical convection and features like low-pressure systems over the north Indian Ocean. It is currently in east Africa with amplitude greater than one, which is not favourable for enhancing the convection over the north Indian Ocean region and hence monsoon rainfall activities, IMD said.
