Even as the threat of heavy to very heavy rain hangs over the disaster-affected hills of North-West India, India Meteorological Department (IMD) has hinted at the formation of a low-pressure area over the monsoon-friendly location of North-West Bay of Bengal next 4-5 days (around Wednesday next), and strengthening of the monsoon from East India onwards.
May grow as depression
businessline had hinted at this likelihood in a report almost a week ago. IMD suspects The ‘low’ may intensify into a depression and stay parked over the North-West Bay for at least two days, causing rains to spread and intensify. So the rain-driving monsoon trough over the plains of North-West and Central India may stay active and south of normal during most days of the week from July 20 to 26.
Rainy outlook for weekend
In a short-term outlook on Friday, the IMD said the fairly widespread to widespread rainfall with isolated heavy to very heavy rain currently over Uttar Pradesh for next two days and isolated heavy rainfall thereafter. Isolated heavy rainfall is also likely over flood and landslide-hit Himachal Pradesh during next five days; over North Haryana during next three days; and East Rajasthan from Friday to Wednesday. Isolated very heavy to extremely heavy rain is likely over Uttarakhand during next five days.
Confluence of factors
This is attributed to the continued confluence of atmospheric systems, including the western end of the monsoon trough that lies south of its normal position. Its eastern end lies north, but may shift to the North Bay from Monday, igniting the ‘low’ a couple of days later. Elsewhere, a cyclonic circulation lies already over West-Central and adjoining South-West Bay, while another hangs over South Uttar Pradesh. The offshore trough though lies truncated from South Maharashtra to Kerala coasts.
Flare-up over East India
The presence of the eastern end of the monsoon trough may continue to cause fairly widespread to widespread rain with isolated heavy to very heavy falls over Assam, Arunachal Pradesh, and Bihar for three more days. Initiation of the ‘low’ may bring isolated heavy rain to Odisha for the next five days and escalate later. A similar outlook is valid for Nagaland and Manipur for four days and plains of West Bengal on Saturday and Sunday. Isolated very heavy to extremely heavy rain is likely over the hills of West Bengal, Sikkim, and Meghalaya until today (Friday) before reducing in intensity.
Monsoon to intensify
The ‘low’ may help intensify the monsoon over the West Coast and West India, apart from bringing a much-needed spell over rain-deficient Central India during next week. The offshore trough may become full-blown from Gujarat to Kerala coasts during many days of the week. Strong westerly to south-westerly winds are likely along the West Coast. Light to moderate fairly widespread to widespread rain may lash parts of the South Peninsula India except over Tamil Nadu. This may help lift the heavy rain regime over extreme northern parts of the country, North-East India, West Bengal, and Sikkim.
Above-normal rain seen
Overall, during the week of July 20-26, normal to above normal rain is predicted over Central India, Gujarat, and western parts of the country covering mainly along west coasts and adjoining South Peninsula. It is likely to be normal over the rest parts of the country, outside parts of the landslide-hit hills of North-West India, Western Himalayan Uttar Pradesh, Bihar, the North-Eastern States, West Bengal, and Sikkim, where it is likely to be normal to below normal.