You are here: Home » Current Affairs » News » National
Business Standard

Western disturbances and missing rains from northwest India in April

After reeling from February 25 till possibly May 1, one of the longest dry spells, the plains of northwest India -- including Delhi are expecting a reprieve due to a Western Disturbance (WDs)

Delhi weather | Rainfall | summer tips

IANS  |  New Delhi 

Longest dry spells this year

After reeling from February 25 till possibly May 1, one of the longest dry spells of 65 days, the plains of northwest India -- including Delhi-NCR -- are expecting a reprieve due to a Western Disturbance (WDs) on May 2.

Incidentally, there were six WDs in April -- on April 1-4, 7-9, 13-15, 20-22, 23-25 and 28-29 -- that have had an impact on northwest India.

But most of them were feeble and dry and moved across the higher ridges of the Himalayas.

"Only last three systems caused gusty winds and dust rising winds and dry thunderstorms at several places, including Delhi NCR, and also dust storms over Rajasthan on April 14, 22 and 25," said India Meteorological Department (IMD) director general (meteorology) Mrutyunjay Mohapatra.

Because of these dry WDs, since 122 years, April has become the hottest months for northwest and central India and fourth hottest.

So what caused these WDs to be dry?

As the name suggests, WDs are extra-tropical systems that originate in the Caspian Sea, Red Sea area and move towards east and traverse over Iran, Afghanistan and Pakistan to reach India.

"If the WDs move across southern latitude, it gets moisture from Arabian Sea, which in turn leads to activity over northwest India. If it does not, its impact will be dry," Mohapatra explained and added: "Of the six WDs in April, only one had southerly trough but the rest moved east-northeast wards."

The reason why these systems were feeble lies in its extra-tropical origin, the IMD DG explained.

"Unlike the tropical systems that are dependent on convective phenomenon, the extra-tropical systems depend upon temperature gradient as determined by temperature difference between north and south in the middle latitude area. If it is more, then WD will have higher energy, it will be more intense and vice versa," he said.

That explains why winters have stronger WDs when the temperature gradient in the Caspian Sea, Red Sea area is higher.



(Only the headline and picture of this report may have been reworked by the Business Standard staff; the rest of the content is auto-generated from a syndicated feed.)

Dear Reader,

Business Standard has always strived hard to provide up-to-date information and commentary on developments that are of interest to you and have wider political and economic implications for the country and the world. Your encouragement and constant feedback on how to improve our offering have only made our resolve and commitment to these ideals stronger. Even during these difficult times arising out of Covid-19, we continue to remain committed to keeping you informed and updated with credible news, authoritative views and incisive commentary on topical issues of relevance.
We, however, have a request.

As we battle the economic impact of the pandemic, we need your support even more, so that we can continue to offer you more quality content. Our subscription model has seen an encouraging response from many of you, who have subscribed to our online content. More subscription to our online content can only help us achieve the goals of offering you even better and more relevant content. We believe in free, fair and credible journalism. Your support through more subscriptions can help us practise the journalism to which we are committed.

Support quality journalism and subscribe to Business Standard.

Digital Editor

First Published: Sun, May 01 2022. 10:32 IST