North witnesses fastest monsoon onset in 52 years

Rains likely to recede in Northwest India

Around June 13-14, the southwest monsoon was stationed around central India and was expected to gradually move towards the northern parts by June-end.

But in a span of just 24-48 hours, there was a sudden gush of moisture-laden clouds that pushed northwards and the entire country was covered with monsoon by June 16, a good month ahead of its scheduled date for the first time since 1961. The rains caught everyone napping and brought untold misery to hundreds of thousands in Himachal Pradesh, Uttarakhand, Rajasthan and parts of Uttar Pradesh. However, intensity of rain will come down in the next three-four days, meteorologists said.

What was this weather phenomenon, which had taken even the best of meteorological minds in the country unawares? (MAPPING RAINFALL)

India Meteorological Department (IMD) officials said it was a rather unexpected clash between moisture-laden clouds from the Arabian Sea and a well-marked western disturbance over Rajasthan, which pulled up the monsoon clouds from central India to the northwest in a record two-three days.

The low pressure area, created because of the western disturbance, is still stationed around Rajasthan, the reason why north India is receiving heavy rains. Rainfall between June 1 and June 17 was 55 per cent more than normal across India. As against a normal of 72.9 millimetres, India received 112.9 millimetres of rainfall during the period.

Former IMD director-general Ajit Tyagi explained if the western disturbance was not present over North India, the southwest monsoon would have been still hovering around the central parts of the country.

“Since the last couple of years, the southwest monsoon has been rather subdued over north India in the month of June. However, this year already the rain-bearing clouds from the Arabian Sea were quite active and when this intersected with the active western disturbance in the north, it quickly pulled up the monsoon over northwest India right up to Pakistan,” Tyagi said.

Was the IMD caught unawares?

Not exactly, said its director of long range forecasting, D S Pai. “We always knew the onset of southwest monsoon in most parts of the country, including north India, will be before time this year. Also, long range forecasts cannot give such daily occurrences; this can only be done through short-range or medium-range forecasts,” Pai said.

A week here and there does not mean IMD failed to gauge the impact, Tyagi said.

Going forward, the intense rainfall of the last few days is expected to subside. Mahesh Palawat, chief meteorologist of Skymet Weather Services, said the western disturbance, blamed for causing intense rainfall over the northwestern parts, is slowly moving towards the eastern parts, which would cause rainfall to subside in the next three-four days. “The low pressure area, built over north India, has also weakened, which will cause rains to subside. But monsoon activity will again gather steam over the North around June 25-26,” Palawat said.

Tyagi, too, expected the rains in north India to subside and move towards the east in the next two-three days.