Saturday, October 03, 2009

Four-month southwest monsoon officially comes to an end

Even as the four-month southwest monsoon officially came to an end on Wednesday, with an overall deficiency of 23 per cent - making it the worst season since 1972, when the deficiency was 24 per cent - the India Meteorological Department (IMD) has forecast more rain in different parts of the country at least for the next week.

According to the IMD, while there could be fairly widespread rainfall over the north interior peninsula during the first half of the next week and over the adjoining areas of central and west India during the second half, scattered rainfall activity is likely over the northeastern States and adjoining east India through the week and over the plains of northwest India during the second half.

The new spell is expected since a well-marked low pressure area lying over west and central Bay of Bengal and adjoining north coastal Andhra Pradesh and south coastal Orissa is likely to move slowly west and northwestwards towards the south Gujarat region.

Withdrawal to extend

A fresh cyclonic circulation or low pressure area is also likely to develop over northwest Bay of Bengal off the Orissa coast around October 5. Further, a western disturbance as an upper air system is likely to affect northwest India from October 4.

Consequently, the withdrawal phase of the monsoon is likely to extend at least beyond the next week. "Due to likely easterly winds and moisture incursion, there is no possibility of further withdrawal of the southwest monsoon during the next [one] week," an IMD press release said.

The monsoon has so far withdrawn from many parts of Rajasthan, Jammu and Kashmir, Himachal Pradesh, Punjab, Haryana and some parts of Uttarakhand, west Uttar Pradesh, and north Gujarat. On Thursday, the withdrawal line passed through Uttarkashi, Aligarh, Sawai Madhopur, Udaipur and Naliya.

Meanwhile, at the official end of the season (the monsoon officially begins on June 1 and ends on September 30), out of the 533 meteorological districts in the country, 41 districts (8 per cent) recorded "scanty" rainfall or a deficiency of over 60 per cent, and 270 more (51 per cent) recorded "deficient" rainfall or a deficiency of between 20 per cent and 59 per cent.

The northwest region comprising Delhi, Haryana, Punjab, Chandigarh, Uttar Pradesh, Uttarakhand, Himachal Pradesh, Jammu and Kashmir and Rajasthan led the table with a deficiency of 36 per cent, followed by the northeast region - which region includes Bihar, West Bengal, Sikkim, and Jharkhand, apart from the northeastern States - with a deficiency of 27 per cent.

Central India, which comprises Maharashtra, Gujarat, Goa, Madhya Pradesh, Orissa and Chhattisgarh, occupies the third place with a deficiency of 20 per cent. The south peninsular region, comprising Tamil Nadu, Pondicherry, Andhra Pradesh, Karnataka, Kerala, Lakshadweep, and Andaman and Nicobar, brings up the rear with a deficiency of four per cent from the normal.

The northwest and the northeast regions were consistently on the back foot right through the season, with the deficiencies remaining above 20 per cent. The northeast witnessed the worst period in the week ending June 24, when the deficiency rose to as much as 55 per cent, while the northwest had its worst time in the week ending July 8, when the deficiency rose to 50 per cent.

In central India, it was a roller coaster ride. Starting with a deficiency of 50 per cent for the week ending June 3, it recorded a maximum deficiency of 73 per cent in the week ending June 24. Following several spells of good rainfall later, the deficiency got wiped out completely by July 22 when the region recorded a surplus of 3 per cent over the long period average. However, the situation subsequently returned to the negative territory, ending up with a deficiency of 20 per cent.

Lucky region

The southern peninsular region has been the most lucky, although the situation seemed to be getting out of control for a brief spell. In the week ending June 24, the deficiency in the region rose to 38 per cent, but came down to 31 per cent the next week. Since then, the deficiency never rose beyond 25 per cent.

However, rainfall was not uniformly good across the region. Andhra Pradesh, particularly the Telengana and coastal Andhra Pradesh regions, had a bad time right through. While Telengana ended with a deficiency of 35 per cent, coastal Andhra Pradesh ended with a deficiency of 25 per cent.

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