Monsoon covers most parts of the country at least a week in advance

New Delhi: Monsoon has covered most parts of the country until Thursday. Usually, monsoon covers all parts of the country by July 8. Now, only parts of Rajasthan; Punjab and Haryana are left to be covered, according to India Meteorological Department (IMD).

Monsoon arrived in Delhi on Wednesday and covered the city and all parts of the national capital region (NCR) on Thursday.

IMD scientists said certain synoptic features this monsoon such as the development of cyclone Nisarga over the Arabian Sea, which coincided with the onset of monsoon over Kerala, and the formation of a low-pressure system over the Bay of Bengal soon after that helped the northern limit of monsoon (NLM) -- the northern-most boundary up to which monsoon rains have advanced -- advance very rapidly over the country.

Monsoon is early over several states by at least a week, IMD’s NLM map showed.

“Monsoon has already covered entire Uttar Pradesh, Himachal Pradesh, most parts of Punjab, Chandigarh, Haryana and entire Delhi as on Thursday. This is because of a number of favourable conditions that helped the monsoon advance. Cyclone Nisarga had formed over the Bay of Bengal on June 1, which coincided with the arrival of monsoon over Kerala. We had a very good low-pressure system formed over the Bay of Bengal (around June 8), which helped monsoon advance both on the east and west coasts. There was a brief lull between July 16 and 22, but rains picked up again. We are seeing a good progression of monsoon,” said K Sathi Devi, head, regional weather forecasting centre.

The monsoon has been 22% excess of the long-period average (LPA) till Wednesday.

LPA is the average rainfall recorded between June and September, calculated during the 50-year period, and is kept as a benchmark while forecasting the quantitative rainfall for the monsoon season every year.

Due to the shift of trough of low-pressure northwards and convergence of strong southerly or south-westerly winds from the Bay of Bengal over the north-east, widespread rain with heavy to very heavy rainfall very likely to continue over the region for the next three to four days, IMD’s Thursday bulletin said.

Light to moderate rains can be expected in Delhi-NCR in the next two to three hours, said Kuldeep Shrivastava, head, regional weather forecasting centre.