15% surplus rain in August first half; monsoon 105% of long period average

India received 153 mm in the first half (1-15) of August, which is 15 per cent above normal of 133.3 mm for the period. It has helped the overall seasonal rainfall to reach 105 per cent of its long period average (LPA) between June 1 and August 15.

The rainfall was 11 per cent deficient in June and 9 per cent surplus in July. The country has received 606.8 mm of rain between June 1 and August 15, which is 4.8 per cent above its LPA of 579.1 mm.

The India Meteorological Department (IMD) had earlier forecast rainfall across the country to be “normal” (94 to 106 per cent of LPA) in August, except many areas in southern parts of central meteorological subdivision and adjoining northern peninsular India, north-east and adjoining areas of east India as well as some parts of north-west and south peninsular India, where “below normal” rainfall has been predicted.

Excess in all regions

Latest data show that the east and north-eastern meteorological subdivision comprising West Bengal, Bihar, Jharkhand and north-eastern States received 198.6 mm of rains in the first fortnight of this month, which is 21.4 per cent more than its LPA of 163.6 mm.

The north-west subdivision, comprising Punjab, Haryana, Rajasthan, Uttar Pradesh, Uttarakhand, Himachal Pradesh, and Jammu and Kashmir, has reported 154.6 mm rainfall — 44.8 per cent more than its normal 106.8 mm during the August 1-15 period.

Central India, comprising Gujarat, Maharashtra, Madhya Pradesh, Chhattisgarh, Odisha, and Goa, has reported 160.9 mm of rainfall, which is 1.5 per cent less than the LPA of 163.4 mm. But, the south peninsula comprising Kerala, Tamil Nadu, Karnataka, Andhra Pradesh and Telangana has reported 99.7 mm rainfall in August 1-15, which is 0.9 per cent above normal of 98.8 mm.

6 met zones deficient

The number of meteorological sub-divisions with deficient rainfall has reduced to 6 from 9 in past 15 days. Out of 36 meteorological sub-divisions, deficient rainfall has been reported from 6 such units, representing 17 per cent of India’s geographical area, as on August 15. Whereas the number of deficient subdivisions was 9 with 25 per cent area until July 31.

Bihar, Punjab, Himachal Pradesh, Jammu and Kashmir and some of the N-E States have received deficient rainfall, so far.

Meanwhile, IMD on Thursday said that active monsoon conditions were observed over most parts of north-west and adjoining central India during week ended August 15. It also pointed out that exceptionally heavy rainfall was observed over Karauli (38cm) in east Rajasthan on August 11, extremely heavy rainfall reported over east Rajasthan on August 11-12, very heavy rainfall over Himachal Pradesh during August 9-11, over Punjab on August 11 and August 14 and over Haryana on three days during August 9-12.

“This was mainly due to a cyclonic circulation remained active in most dates during the week over the region and it was persisted over north-east Rajasthan and neighbourhood. Besides, convergence of moisture laden southerly and south-westerly winds from Arabian Sea to north-west India also observed at lower levels,” IMD said.

ENSO-neutral conditions

Currently, neutral El Nino-Southern Oscillation (ENSO) conditions are prevailing in the equatorial Pacific region, it said and said that La Nina is likely to develop towards end of August as suggested by forecasts from the Monsoon Mission Climate Forecasting System (MMCFS).

IMD said the Madden Julian Oscillation (MJO) index, another global weather pattern that influences monsoon rainfall, is currently in phase 1 with amplitude more than 1. MJO is likely to contribute to enhanced convection starting from around August 20-21 over the Equatorial Indian Ocean and adjoining Arabian Sea and Bay of Bengal, it said.

The weather bureau has advised farmers of Uttar Pradesh, Rajasthan, Madhya Pradesh, Chhattisgarh, West Bengal, Odisha, Jharkhand, Bihar, Punjab, Haryana, Tamil Nadu, Kerala, Karnataka and Rayalaseema region to drain out excess water from field crops and horticultural crops.

“Overall, rainfall is likely to be above normal over plains of north-west and central subdivisions and near normal over western Himalayan region,” it said in its forecast until August 22.