Tuesday, Aug 09, 2022

Light Rain Likely In Delhi City

Delhi city is expecting light rain in the coming days. It will be a relief from the tremendous heat waves enveloping the city.

Delhi rain (Representative image) PTI

Delhi is likely to some respite from the punishing heat Wednesday evening onwards, with the weather department predicting pre-monsoon thundershowers and light rain.

Monsoon is predicted to reach the capital either on Thursday or Friday.

The Safdarjung Observatory, Delhi's base station, recorded a minimum temperature of 28.8 degrees Celsius. The maximum temperature is predicted to settle at 41 degrees Celsius.

The city has been reeling under high humidity and soaring temperatures for a week now.

On Tuesday, the Safdarjung Observatory had logged a maximum temperature of 41.5 degrees Celsius but the heat index or "real feel" was recorded at 53 degrees.

The web bulb temperature had also jumped to 33.7 degrees, the highest so far this year.

The heat index (HI) is what the temperature "feels like" to the human body when relative humidity is combined with the air temperature. HI is calculated for shady areas.

Whereas, wet-bulb temperature is the lowest possible temperature that can be reached through evaporation of water in any given air condition. It takes into account temperature, humidity, wind speed, sun angle, and cloud cover etc. and is considered the best metric to calculate and monitor heat stress on the human body.

A wet-bulb temperature of 35 degrees is considered the maximum limit of humidity that humans can handle. Beyond this, the body can no longer effectively cool itself through perspiration.

According to the India Meteorological Department, Delhi is likely to receive the first monsoon showers on Thursday or Friday.

The IMD has issued an orange alert, warning of moderate rainfall in the city on June 30. The maximum temperature will come down to 33-34 degrees Celsius by July 1.

The southwest monsoon usually arrives in the national capital on June 27.

Senior IMD Scientist R K Jenamani said there is a prediction of good rainfall in the city on June 30 and the arrival of the monsoon can be declared on Thursday or Friday.

Pre-monsoon convection may lead to light rainfall in the national capital on Wednesday evening and provide relief from the heat, he said.

Last year, the IMD had forecast that the monsoon would arrive in Delhi nearly two weeks before its usual date. However, it reached the capital only on July 13, making it the most delayed in 19 years.

The monsoon had entered a "break" phase and there was virtually no progress from June 20 to July 8.

Asked about the delay in the arrival of the monsoon in Delhi, the senior scientist said a gap of around five days is considered normal.

"However, we did not see any major weather system developing in the Bay of Bengal (which could have pushed the monsoon forward). This year, it has mainly been a wind-driven monsoon," he said.

According to IMD data, the monsoon covered Delhi 29 times in June and 33 times in July in the last 62 years.

The IMD had in 2020 revised the date of monsoon arrival in Delhi from June 29 to June 27.

Weather experts have said the monsoon is expected to yield good rainfall in Delhi in the first 10 days and help cover the rain deficit.

Since June 1, when the monsoon season starts, Delhi has received just 24.5 mm of rainfall against the normal of 66.7 mm. All of it came between June 16 and June 20.