Kathmandu, June 4

The Meteorological Forecasting Division has said Nepal is likely to welcome monsoon a few days ahead of the normal onset date this year.

Though the tentative date for arrival of monsoon in the eastern part is June 10, it may make an onset in Nepal by June 8, two days earlier, provided the dominant westerly component is not disturbed while advancing into the country from the Bay of Bengal, said Rishi Ram Sharma, director general at the Department of Hydrology and Meteorology, which oversees MFD.

“In South Asia, the southwest monsoon picks up more moisture from the Bay of Bengal and heads towards north-east India. As information received so far from the weather maps and satellite images show that monsoon has already developed over the east and central Bay of Bengal and central Bangladesh, Nepal is likely to experience monsoon a few days prior to the normal onset sate,” read a monsoon watch released by the MFD.

Once the monsoon enters from the eastern region, it makes progressive westward advancement to the remaining parts of the country over the next few days through the central region. Meteorologists said the conditions looked favourable for arrival of monsoon before the scheduled date. The monsoon lasts for an average of 105 days.

Nepal receives an average of 80 per cent of annual rainfall during the monsoon, which originates in the Bay of Bengal and moves along the southern flanks of the Himalayas, bringing rains to Nepal. The average annual rainfall in Nepal is 1,600 mm, but it varies from place to place depending on climatic conditions.

Monsoon is the wettest season and is the main source of precipitation in Nepal. The effect of monsoon is prominent in the eastern part of the country. The northern and mid-western regions are generally drier compared to the eastern parts.

The driest regions Mustang, Manang and Dolpa receive less than 150 mm of rainfall while the wettest region Kaski receives more than 4,500 mm rainfall during the monsoon season.

The DoHM said only three monsoons have been recorded to have arrived on time since 1968.