Monsoon favourable, likely to cover deficiency soon, says IMD
The first 45 days of the four-month south-west monsoon so far have been favourable for agriculture with 17 states receiving normal rain, 10 receiving excess and two receiving “large excess,” rain, the India Meteorological Department (IMD) said on Wednesday.
Delhi, which had a deficiency of 46% until Tuesday, received rain in many parts of the city on Wednesday morning. Parts of Noida and Greater Noida in the National Capital Region (NCR) also received rain.
“We are expecting moderate category rain on July 17, 18 and 19 which will help cover the deficiency. There is a cyclonic circulation over Uttar Pradesh and the monsoon trough is also likely to bring rains over the city,” said Kuldeep Shrivastava, head of the IMD’s Regional Weather Forecasting Centre.
Only Jammu and Kashmir and Ladakh are in the “large deficient” category. Apart from Delhi, Himachal Pradesh, west Uttar Pradesh, Manipur, Mizoram, Kerala and Dadra and Nagar Haveli are also rain-deficient.
The rain deficiency in northwest India will be covered soon, according to IMD scientists. “As of now, there is a slight deficiency in northwest India which is likely to be covered. Rest of India has got very good rains. Rains will further improve in August and September,” said DS Pai, senior scientist at IMD, Pune.
Monsoon rains this year were marked by floods and extremely heavy (over 20 cm rain) in Assam, Bihar and eastern Uttar Pradesh, landslides in Arunachal Pradesh and record rainfall in Saurashtra.
A cool El Niño Southern Oscillation (ENSO) neutral phase is prevailing, Pai said. El Nino is a climate pattern characterised by high sea surface temperatures in the tropical Pacific Ocean which are neutral now. El Nino years in India are linked to below-normal monsoon rains and higher than normal frequency of heat waves. Last year, weak El Nino conditionsled to a delayed onset of the monsoon according to scientists.
A cool El Nino neutral phase indicates that the sea surface temperature is cooler than normal in the tropical Pacific Ocean. “There is no La Nina (La Niña is characterized by unusually cold ocean temperatures in the Equatorial Pacific) phase yet. But cool El Nino neutral conditions favour a normal monsoon over India. Further cooling will ensure more rains in August and September,” added Pai.
IMD last month said there is an enhanced probability for development of weak La Niña conditions after the monsoon season, which begins in June and runs till the end of September.
“Except for six subdivisions, the distribution of monsoon rains have been very good this year,” said M Mohapatra, director general, IMD.
Under the influence of a strong lower level wind convergence along the west coast and an east-west shear zone, widespread and very heavy rains are likely in Konkan and Goa, Madhya Maharashtra and Gujarat during the next five days, IMD said in its Wednesday bulletin, adding that strengthening of lower level easterlies and the monsoon trough which is passing over parts of northwest India may cause widespread and heavy rains over the northern plains on July 18 and 19.
IMD experts said this monsoon is marked by a lot of moisture incursion from the Arabian Sea as opposed to the Bay of Bengal and frequent oscillation of the monsoon trough (line of low pressure) to the north of its normal position. The normal position of the monsoon trough is between Ganganagar in Rajasthan and the Bay of Bengal.
“We are seeing a high convergence of strong, moist westerly and southwesterly winds at lower levels from the Arabian sea. It happened between July 2 and 4, again from July 5 and 7 and now again we are seeing the same pattern so the west coast and Gujarat have got very good rains. No system has developed over the Bay of Bengal. Another feature of this monsoon is the frequent oscillation of the trough to the north and sometimes to the south of its normal position which gave us very good distribution of rains even in Jharkhand, Chhattisgarh, Marathwada, Rayalaseema and Telangana,” said RK Jenamani, senior scientist at the national weather forecasting centre.
The monsoon trough is likely to move northwards again between July 19 and 20, which will likely lead to rains in the Himalayan foothills.
Okha in Gujarat registered an all-time record with 48 cm of rain on July 7. On July 5, Khambala, Kalyanpur and Porbandar recorded 49 cm, 36 cm and 29 cm respectively. Mumbai received over 15 cm rain on Tuesday evening and Wednesday morning in two short spells.
Predictions of a bountiful monsoon have spurred hopes of a rural sector-led economic recovery. The June-September monsoon is critical to agriculture and the wider economy. A poor monsoon hits incomes because agriculture employs nearly half of all Indians. The rains are a lifeline for about 60% of the country’s net cultivated area, which has no irrigation.