Thiruvananthapuram, Sept. 5
THE southwest monsoon has swung back into action in peninsular India with most parts receiving fairly widespread rains with isolated heavy rainfall during the 24 hours ending Monday morning.
However, this has been matched only by a corresponding decline in recorded rainfall in both the west and northwest regions. Monsoon has already exited the west, and is in the process of doing so in at least parts of the northwest as well.
There has been a 51 per cent shortfall in all-India rainfall recorded week-on-week as per latest statistics available (week ending August 31). The actual rainfall recorded for the week has been 24.5 mm against a normal of 49.9 mm.
As for the season (June 1 - August 31), the overall deficit has slid from 3 per cent below normal the previous week to 6 per cent below normal. However, the area-weighted percentage of realised rainfall has managed to reach 76 per cent of the normal.
Among the southern States benefiting directly from the latest monsoon pulse are Tamil Nadu and Pondicherry, Karnataka, Kerala and Lakshadweep. The pulse has had a welcome rub-off effect on certain others such as Andhra Pradesh, Konkan, Goa, Madhya Maharashtra, Orissa, Chhattisgarh, east Madhya Pradesh and even the Northeastern States.
A weather update by the National Centre for Medium Range Weather Forecasting (NCMRWF) on Monday said the upper air cyclonic circulation located the previous day over Telangana and neighbourhood has shifted to north interior Karnataka and the neighbourhood.
A trough is seen running in the lower levels linking this system to southeast Rajasthan. The anti-cyclonic circulation over northwest India at 3.1 km above mean sea level also persists.
Forecast for the next 3-4 days said scattered to fairly widespread rainfall is likely over Kerala, Lakshadweep, Karnataka, Konkan, Goa, Gujarat, Madhya Maharashtra, Marathwada, sub-Himalayan West Bengal, Bihar, northeast India, east Uttar Pradesh and Uttaranchal. Isolated heavy rainfall is likely over Konkan, Goa, sub-Himalayan West Bengal, Sikkim, Karnataka, Kerala and Lakshadweep during the next two days.
The rainfall activity is likely to increase further over Tamil Nadu, south coastal Andhra Pradesh, Kerala and Karnataka with the existing east-west shear zone bearing down further over the peninsula in the next 2-3 days.
In a special update on weather conditions in the northwest, the NCMRWF said the region received good rainfall activity during first three weeks of July due to the interaction of the monsoon systems with the eastward moving western disturbances. But subsequently, most parts of the plains received only deficient to scanty rainfall in a trend that has continued till the week ending August 31.
This has compounded the moisture stress for various standing dry crops in the region, apart from raising the requirement of water for irrigated crops. The district-wise cumulative rainfall distribution shows that many of them are in deficient to scanty categories. The region is likely to witness mainly dry weather situation during next week, leading to further deterioration of conditions.
According to zone-wise rainfall analysis (as on August 31) by the NCMRWF, only Central India (+3 per cent) and the South Peninsula (+4 per cent) returned nominal surplus figures while both the Northwest and the Northeast ran identical large deficits (-16 per cent each).