IMD made string of wrong forecasts for arrival of monsoon in Delhi, here’s reason behind it

Representational Image (Credits: PTI)

New Delhi: The India Meteorological Department (IMD) had made a series of wrong forecasts for the arrival of monsoon in the national capital. The IMD on June 17 had predicted that the Capital will witness “moderate rainfall and thunderstorms” on the weekend as the monsoon hits the region, more than 10 days ahead of its usual onset date this year. However, the residents of Delhi spent the entire weekend sweating without even a drop of relief, and this wasn't the Met department's only inaccurate forecast. 

The string of inaccurate weather forecasts, being made by the Met department, began from June 11, which was predicted as the set date for the arrival of monsoons in Delhi. 

“A low-pressure area over northwest Bay of Bengal and the formation of a trough over the region is showing favourable conditions for the advancement of south-west monsoon in most parts of northwest India,” the forecast said.

This forecast was updated on June 13, in which the Met department said, “conditions were favourable for further advancement of south-west monsoon into most parts of Madhya Pradesh, parts of eastern Uttar Pradesh, Delhi, Haryana and Punjab” by June 14.

But the weather department again updated their forecast two days later and revised the monsoon arrival date again.

“Due to the adverse influence of mid-latitude westerlies, a hiatus in the further advancement of south-west monsoon into remaining parts of northwest India is seen. The situation is being monitored continuously and will be updated on a daily basis,” the revised forecast read.

The Met officials stated that this string of wrong short-term and long-term predictions turned out to be inaccurate due to some “volatile” and unforeseen weather conditions unique to northwest India this year. 

It has been nearly two weeks since the original monsoon forecast made by the Met department and the national capital is yet to see any significant rainfall activity in the region. 

According to a report in Hindustan Times, Kuldeep Srivastava, head of IMD’s regional weather forecasting centre said that “Between June 10 and June 15, the low-pressure system was advancing very fast till eastern Uttar Pradesh. However, after that, even though the trough has persisted, the low-pressure system is not as intense.”

According to the reports, the IMD’s long-range forecasts are only around 50% accurate, while short-range forecasts can be 70-80% accurate. However, the weather experts state that the predictions by the Met department are expected to improve further over time.

“There are a few factors that come in the way of accurate weather forecasts. Firstly, northwest India as a region is a little volatile in its weather activities, which makes it slightly trickier to make on-point forecasts compared to other parts,” a senior IMD official said.

“Another reason is that the models that we use for forecasting have its limitations. We will probably be able to improve with better technology,” the official added.