TEHRAN – The monsoon, which has arrived a week later this year in the southern Indian subcontinent, will soon reach the shores of Sistan-Baluchestan province, southeastern Iran, IRNA news agency reported on Monday.

The onset of the monsoon occurs over the Bay of Bengal in May and after about 40 days in the middle of July, moves toward the southern shores of Sistan-Baluchestan province, Mohammad Reza Salari, head of Chabahar marine meteorological department said.

Signs of Monson's arrival first show up with swell (a series of mechanical waves that propagate along with the interface between water and air and thus are often referred to as surface gravity waves), he explained.

After the soil is moisturized and if the synoptic conditions are available, the monsoon rains begin, he added.

Based on the long-term models, it is predicted that this year’s monsoon rains in the southeast of the country will meet normal and above the normal average, he said.

The Indian Ocean’s monsoon winds below from the sea to lands in the summer, which moderates the temperature of the air, especially in the coastal areas, and moisturizes the land, he noted.

He continued that normally, scorching heat hits South Asia during the summers, which leads to a low pressure on land and high pressure in the neighboring oceans, such as the Indian and Pacific Oceans; so that pressure difference between the two systems causes wet winds from the sea to land.

The summer rainfall is a result of the convergence of wind flow from the sea, in large areas of the Indian subcontinent, Pakistan, southern and southeastern Iran, he stated, adding, the monsoon lasts until September, when the air temperature decreases on land and the synoptic pattern changes, the direction of the wind changes and blows from land to sea.

Monsoon rains in India do not contribute significantly to the Sistan-Baluchestan rainfall, but in some years the rainfall has met above normal levels. Not all of this season's rains are monsoon, but the rains may be the result of hurricanes in the northern Indian Ocean, he concluded.

The monsoon of South Asia is among several geographically distributed global monsoons. It affects the Indian subcontinent, where it is one of the oldest and most anticipated weather phenomena and an economically important pattern every year from June through September, but it is only partly understood and notoriously difficult to predict. Several theories have been proposed to explain the origin, process, strength, variability, distribution, and general vagaries of the monsoon, but understanding and predictability are still evolving.

The unique geographical features of the Indian subcontinent, along with associated atmospheric, oceanic, and geophysical factors, influence the behavior of the monsoon. Because of its effect on agriculture, on flora and fauna, and on the climates of nations such as Bangladesh, Bhutan, India, Nepal, Pakistan, and Sri Lanka — among other economic, social, and environmental effects — the monsoon is one of the most anticipated, tracked, and studied weather phenomena in the region. It has a significant effect on the overall well-being of residents and has even been dubbed the "real finance minister of India".

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