15% Surplus Rain in First Half of August; Monsoon at 105% of Long Period Average
By 2024-08-16 12:26:51
15% More Rainfall in August's First Half; Monsoon at 105% of Long-Term Average
La Niña Likely to Develop by Month-End, Says IMD
India experienced 153 mm of rainfall in the first half of August (August 1-15), which is 15% above the normal 133.3 mm for this period. This increase has pushed the overall seasonal rainfall to 105% of the long period average (LPA) for the monsoon season spanning June 1 to August 15.
Earlier in the season, June recorded an 11% rainfall deficit, while July saw a 9% surplus. Between June 1 and August 15, the country received a total of 606.8 mm of rain, which is 4.8% above the LPA of 579.1 mm.
The India Meteorological Department (IMD) had previously forecasted that August rainfall across most parts of the country would be "normal" (94 to 106% of LPA). However, below-normal rainfall was predicted for several regions, including southern parts of central India, the northern peninsular region, parts of northeast India, and some areas in northwest and south peninsular India.
Regional Rainfall Patterns
The latest data reveals that the east and northeast regions, including West Bengal, Bihar, Jharkhand, and the northeastern states, received 198.6 mm of rainfall during the first half of August, which is 21.4% above the LPA of 163.6 mm.
In the northwest region, which includes Punjab, Haryana, Rajasthan, Uttar Pradesh, Uttarakhand, Himachal Pradesh, and Jammu & Kashmir, rainfall totaled 154.6 mm—44.8% above the normal 106.8 mm for the same period.
Central India, encompassing Gujarat, Maharashtra, Madhya Pradesh, Chhattisgarh, Odisha, and Goa, reported 160.9 mm of rainfall, just 1.5% below the LPA of 163.4 mm. Meanwhile, the southern peninsula, including Kerala, Tamil Nadu, Karnataka, Andhra Pradesh, and Telangana, received 99.7 mm of rainfall, which is 0.9% above the normal 98.8 mm.
*Reduction in Deficient Rainfall Areas*
The number of meteorological subdivisions with deficient rainfall has decreased from 9 to 6 over the past 15 days. As of August 15, these 6 subdivisions, representing 17% of India’s geographical area, have reported deficient rainfall. In comparison, 9 subdivisions, covering 25% of the area, were deficient as of July 31. Regions like Bihar, Punjab, Himachal Pradesh, Jammu & Kashmir, and parts of the northeastern states have experienced deficient rainfall so far.
*Active Monsoon Conditions and Weather Events*
The IMD reported active monsoon conditions across most parts of northwest and central India during the week ending August 15. Notable weather events included exceptionally heavy rainfall in Karauli (38 cm) in east Rajasthan on August 11, extremely heavy rainfall in east Rajasthan on August 11-12, and very heavy rainfall in Himachal Pradesh from August 9-11, Punjab on August 11 and 14, and Haryana from August 9-12.
This weather activity was largely due to a persistent cyclonic circulation over northeast Rajasthan, coupled with moisture-laden southerly and south-westerly winds from the Arabian Sea moving into northwest India.
*ENSO-Neutral Conditions and La Niña Outlook*
The IMD noted that neutral El Niño-Southern Oscillation (ENSO) conditions currently prevail in the equatorial Pacific region, with La Niña expected to develop towards the end of August, according to forecasts from the Monsoon Mission Climate Forecasting System (MMCFS).
The Madden-Julian Oscillation (MJO), another global weather pattern influencing monsoon rainfall, is currently in phase 1 with an amplitude greater than 1. The MJO is expected to enhance convection starting around August 20-21 over the equatorial Indian Ocean and adjoining Arabian Sea and Bay of Bengal.
*Agricultural Advisory*
Farmers in Uttar Pradesh, Rajasthan, Madhya Pradesh, Chhattisgarh, West Bengal, Odisha, Jharkhand, Bihar, Punjab, Haryana, Tamil Nadu, Kerala, Karnataka, and the Rayalaseema region have been advised to drain excess water from their field crops and horticultural crops.
Overall, the IMD forecasts that rainfall is likely to be above normal over the plains of northwest and central India and near normal over the western Himalayan region until August 22.
