Why monsoon will late? when will monsoon start in India 2021


Why monsoon will late when will monsoon start in India 2021, rainfall, rain, monsoon, late monsoon, monsoon in india, heavy rainfall
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The monsoon is predicted to arrive in Delhi and surrounding areas this July. According to meteorological experts, the monsoon usually arrives between June 27 and 29, but it has been delayed this year. The monsoon will not reach western Uttar Pradesh, Haryana, Punjab, or Delhi by these dates, according to the Indian Meteorological Department (IMD).

What does it mean ‘onset of monsoon’?

The arrival of the monsoon over Kerala marks the start of India's four-month, June-September southwest monsoon season, which brings more than 70% of the country's annual rainfall. Every year, the beginning is a significant day for the Indian economy.

The southwest monsoon is eagerly anticipated, and the IMD only declares it when certain well-defined and measurable parameters are met. Meteorologists examine the consistency of rainfall over a specific geographic area, as well as its intensity and wind speed. wind and temperature-related conditions must be met.

Is a delay in the monsoon's arrival unusual?

No, not at all. While the monsoon arrived on time last year, reaching the Kerala coastal area on 1st June 2020, the IMD predicted a six-day delay in 2019 — and predicted the onset on June 6. On June 8, 2019, the monsoon arrived.
In the previous two years, 2018, and 2017, the monsoon arrived early, on May 28 and 30, respectively, over Kerala.

Every year, the Andaman and Nicobar Islands receive monsoon rainfall between May 15 and May 20, and the Kerala coast receives monsoon rainfall sometime in the last week of May. However, the onset is not officially declared if the prescribed conditions are not met.

Is a delayed monsoon causes a poor monsoon?

Nope, it doesn't. An onset is simply an event that occurs during the course of the monsoon over the Indian subcontinent. The timing of the onset — a few days late or a few days early — has no bearing on the amount or quality of rainfall during the four-month monsoon season.

Every year, India receives approximately 116 cm of rain, with approximately 89 cm falling during the southwest monsoon season. The total amount of rain that India receives during a particular southwest monsoon season, as well as its regional distribution, is unaffected by the date of the monsoon's onset in that year.

In a recent year, for example, the monsoon arrived two days early and rained heavily for about ten days after that, but the season as a whole produced 14% less rain.

does a delayed onset mean it will delay across the country?

It is true that a delayed onset has the potential to delay monsoon arrival in other parts of the country as well, particularly in the southern states, which begin receiving rainfall within these days of the monsoon reaching Kerala coastal area.

However, this is not a given — a delayed onset does not invariably translate into a delayed arrival across the entire country.

The northward movement of the monsoon after it reaches the Kerala coast is determined by a variety of local factors, including the formation of low-pressure areas. As a result, despite the fact that the onset occurs late, other parts of the country may begin earlier.


This year's monsoon has been delayed due to a number of factors. The first factor, known as the MJO factor, is active in the eastern African region. Senior IMD scientist R K Jenamani explained the system's impact and how it affects the arrival of the monsoon in India, which is thousands of kilometers away.

“Monsoon is a global phenomenon, not a local system,” Jenamani explained.. As a result, a number of factors influence the progress of the southwest monsoon in the Indian subcontinent. The monsoon system is influenced not only by systems in the Indian Ocean but also by those in the Pacific and Atlantic Oceans. This is especially true in the world's tropical regions.

In 1971, two American scientists, Maiden and Julian, discovered the MJO (Maiden Julian Oscillation). They discovered that the monsoon continues to be active in tropical areas in the form of waves. As a result, this oscillation occurs in the equatorial region.”

He went on to say, "This oscillation occurs every thirty days." The impact of the oscillation was minimal when the monsoon was strong over the last few days. However, it is now becoming active in the Indian Ocean. The cloud cover in the subcontinent will decrease as soon as it becomes active in the Indian Ocean. As a result, not only will the monsoon be weak in Delhi, but it will be weak across the country for at least a week.”


Aside from the African system, western disturbance from Europe's mid-altitude regions is also contributing to the monsoon's delayed arrival in northwestern India.

Normally, these systems remain operational throughout the winter. However, several western disturbances have remained active in May and June this year. Two such systems formed in June, influencing the monsoon's movement from east to west. 
Jenamani, an IMD scientist, explained how western disturbances affect the monsoon's arrival in Delhi and the surrounding areas.“When monsoon winds were moving from eastern Uttar Pradesh to western UP and Delhi, a sudden western disturbance produced westerly winds, which pushed the monsoon system east,” he explained. The westerlies have pushed back the monsoon pulse that was coming from the Pacific Ocean and the South China Sea. There will be no wind from the east for at least a week. As a result, there is no chance of monsoon arriving during this time.”


High humidity is another issue that Delhi and its surrounding areas face. Normally, humidity follows a few spells of rain, but this time, despite the late arrival of the monsoon, the humidity level is quite high.

“High humidity is due to the rains that were witnessed in the month of May,” said Kuldeep Srivastava, director of the Delhi Regional Meteorological Centre. The soil has a high moisture content following cyclonic rain. When the sun shines brightly, the moisture in the air raises the humidity and makes for an unpleasant experience.”

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