Monsoon takes a ‘break’, won’t hit NCR soon: IMD

This spell, officials of the India Meteorological Department (IMD) said, will likely get heavy rainfall confined to north-east India and subdued showers in the remaining parts of the country till at least July 5.

The southwest monsoon is on a small “break”.

Monsoon forecasts have been wrong repeatedly this year. (ANI file photo)

Weather scientists said on Saturday that the monsoon was unlikely to progress towards Delhi-NCR and neighbouring states of Haryana, Uttar Pradesh, Rajasthan and Punjab for at least a week as it was entering a “break spell” from June 29 apart from unfavourable conditions that were not likely to spur it further on its path.

This spell, officials of the India Meteorological Department (IMD) said, will likely get heavy rainfall confined to north-east India and subdued showers in the remaining parts of the country till at least July 5.

“Models suggest monsoon entering into a break spell from June 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 decide quantum of seasonal rainfall,” tweeted M Rajeevan, secretary, ministry of earth sciences.

He added that this “break” is normal for monsoon weather systems and usually lasts around a week, but it could affect agriculture if it continues for a longer duration. India receives about 70% of its annual rain during the four-month monsoon that is crucial for rice, soybean, and cotton cultivation.

Monsoon forecasts have been wrong repeatedly this year. IMD’s May 31 forecast for early onset over Kerala -- which marks the arrival of monsoon to India -- raised hopes of fast advance across the country. But the Met department revised this at the last minute, on May 30, and said monsoon will arrive in India on June 3 -- two days later than normal schedule.Then again on June 11, IMD forecast that monsoon will advance to remaining parts of the country outside south Rajasthan and Kutch in the next six to seven days. But monsoon rains have still not covered most parts of northwest India.

For Delhi, the Met had announced that monsoon will hit the national capital between June 12 and 15 — nearly two weeks ahead of the normal onset date of June 27. But that too didn’t happen as the system slowed down.

From June 1 to June 26, the country has recorded 20% excess rain — 43% excess rain over northwest India, 36% over central India, 3% over east and northeast India, and 7% over south peninsula. However, out of 36 subdivisions, 7 recorded large excess rain (60% or more above normal), 14 saw excess rain (20 to 59% above normal), 7 saw normal rain (-19% to 19%) and 8 recorded deficient rain (-20% to -59%).

According to IMD data till Saturday, the northern limit of monsoon (NLM) — the northernmost boundary up to which rains have advanced — was passing through Rajasthan’s Barmer, Bhilwara and Dholpur, Uttar Pradesh’s Aligarh, and Meerut, Haryana’s Ambala and Punjab’s Amritsar. It has been at the same position for a week.

“... prevailing meteorological conditions, large scale atmospheric features and the forecast wind pattern by dynamical models 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 during next 7 days,” IMD said in its daily weather bulletin on Saturday.

The bulletin noted subdued rainfall is “very likely” to prevail over northwest, central and western parts of peninsular India during the next 5 days, and will merge into the “break monsoon” spell from June 29. However, strong moist south-westerly winds are expected to lead to widespread rainfall over West Bengal, Sikkim and other northeastern states during the same period, IMD said.

NO SIGN OF REVIVAL FOR NOW

Meteorologists said a revival in the pace of monsoon is unlikely for the first week of July due to unfavourable weather conditions, and little is known beyond that.

“Monsoon will not cover remaining parts of the country until conditions become favourable. Large scale features are not supporting monsoon progress and activity. Some of these include — cross equatorial flow has weakened; (there is) no convection over Arabian Sea and Bay of Bengal, and the winds are also unfavourable. Mid latitude westerlies have strengthened; the Madden-Julian Oscillation (MJO) is also not over the Indo-Pacific region,” said RK Jenamani, senior scientist at the National Weather Forecasting Centre, IMD.

The Madden Julian Oscillation is a weather phenomenon whose location and amplitude strongly affect low pressure systems, and in turn, monsoon rains.

Another scientist pointed out on Saturday that the timing of the “break” monsoon spell this year is different from what is normally seen.

“Normally, a break monsoon phase happens when 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 Bay of Bengal and hence little convective activity. During break monsoon phases, rains are limited to north-east India. But this time the trough is not near the Himalayan foothills but the monsoon flow itself has weakened,” said OP Sreejith, head of climate monitoring and prediction group at IMD Pune.

“Up to July first week, there are no indications of monsoon reviving. 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,” he said.

Sreejith added that monsoon may only revive when a low-pressure system forms over the Bay of Bengal, and “we haveno information” on that as of now.

Usually, monsoon covers all parts of the country by July 8.