New Delhi/Bengaluru: The month of July will witness “above normal” rainfall and temperatures across most of the country, said Mrutyunjay Mohapatra, director general of the India Meteorological Department (IMD), in a press conference on July 1.
The low-pressure activity was particularly low in June, causing below-normal monsoonal activity in June, and was also one of the reasons the heatwave in mid-June was so extreme, said Mohapatra. June was the warmest ever that northwest India has witnessed in 123 years, he added.
According to news reports, at least 277 people died in New Delhi alone over a nearly two-week-long heatwave in mid-June. The days that followed the heat wave also witnessed extremely heavy rains and flooding in the national capital. Heavy showers in the early hours of June 28 too broke records, with Delhi getting 91 millimetres of rainfall in just one hour was “similar to a cloudburst”, according to Mohapatra.
While no entity across the world has been able to predict cloudbursts, plans are on to get three more radars for the region to increase predictive power for the national capital, Mohapatra added. Improving our observation systems and weather models will greatly help increase the predictive power when it comes to such weather phenomena, he added.
June: Below-normal rainfall, high temperatures
The onset of the southwest monsoon occurred on May 30 over Kerala, two days before the usual onset date of June 1 over the state. The first month of the monsoon, however, experienced below-normal monsoonal activity: rainfall in June was nearly 11% below normal across the country, said M. Mohapatra, director of the India Meteorological Department, in a virtual press conference on July 1.
This below-normal rainfall during June was due to three main factors, including a slow onset of monsoonal activity over the northern and eastern parts of the country, and the development of just one low-pressure system (across just three days) versus the usual three systems (across 11 days) in the subcontinent, Mohapatra said.
The development of only one low-pressure belt is also one of the causes of the higher temperatures that Delhi and the northwestern region witnessed in June, said Mohapatra.
Northwest India was the most affected due to the rising temperatures, and it was the warmest June that the region witnessed since 1901 in terms of maximum temperatures, Mohapatra said.
It was a particularly hot June for northwest India. The temperature in many parts of Delhi hovered between 45-50 Degrees Celsius ranges in mid-June. According to news reports, at least 277 people died in New Delhi alone over the nearly two-week-long heatwave.
From burning to drowning
The days that followed the heat wave witnessed extremely heavy rains that resulted in flooding in many parts of the national capital. Mishaps abounded, including the collapse of a portion of the roof in Delhi airport which killed at least one person and injured several others. Images of flooded homes and roads, and cars and buses drowning in rainwater went viral on social media. The city is currently on orange alert for heavy rainfall till July 2.
The rains that New Delhi witnessed on June 28 were record-breaking, Mohapatra said in the virtual press conference. He gave the example of rainfall readings in Delhi University and Lodhi Road in Delhi for this. Between just 0500 and 0600 hours Indian Standard Time on June 28, Delhi University clocked 91 millimeters of rain, Mohapatra said. Safdarjung alone witnessed 228.1 mm of rainfall over a 24-hour period on this day. As per a report by the Indian Express, a breach in the Barapullah drain wall led to flooding in south, southeast and New Delhi.
“This was not a cloudburst but similar to a cloudburst,” Mohapatra said.
Currently, the IMD obtains data on cloud cover for Delhi from three radars; radars provide a higher detection of clouds and, therefore, cloudburst possibilities. To get more accurate predictions for the region, plans to get three more radars are in the works as more radars also mean more combined predictive power, said Mohapatra.
‘Prediction power needs to improve’
“There are certain situations where predictions are virtually impossible…and this is a challenge not only in India but across the world,” he said. Cloudbursts are one of them, said Mohapatra. Improving India’s observation systems and weather models will greatly help improve the predictive power when it comes to such weather phenomena, he added. Since the heavy showers similar to a cloudburst happened in an urban area like Delhi, it had even more adverse impacts, according to Mohapatra.
“We will have in place a proper system for Delhi…certainly it will improve our performance in future,” said Mohapatra. “We predicted the heavy showers at 0152 hours [on June 28], one and a half hours before [the rains began by 0300 hours]. That needs improvement…we need to improve this by three to six hours.”
Parts of east and north eastern India (including Sikkim, Assam and West Bengal) also experienced very heavy rainfall from June 12 to June 20. Assam witnessed floods. Mawsynram in Meghalaya recorded 64 centimeters of rainfall on June 15, and 78 cm on June 18.
What’s to come in July
El Niño conditions have stopped, and we are currently in ENSO neutral conditions, said Mohapatra. The La Niña will prevail over the second half of the monsoon, he added.
The El Niño Southern Oscillation (ENSO) is a complex climate pattern that depends on fluctuating sea surface temperatures and atmospheric changes in the tropical Pacific Ocean. The ENSO occurs in three phases: the almost contrasting El Niño and La Niña phases, and the ENSO neutral phase. While many droughts in India during the monsoons are tied to the impacts of an El Niño, the La Niña is usually associated with wetter conditions and above-normal rainfall. During an ENSO neutral phase – like what India is currently witnessing – neither an El Niño or La Niña are at play.
July will bring above-normal rainfall – a whopping 106% more – across most of the country. While this would be good for agricultural practices in some areas, some others may witness local flooding, Mohapatra said.
July will also witness above-normal maximum temperatures, as well as above-normal minimum temperatures (due to higher cloud cover) in many areas, meaning that it will be warmer than is normal in July in many parts of the country.
Currently, the IMD has issued a red alert for extremely heavy rainfall in several states – Arunachal Pradesh, Tripura, Sub-Himalayan West Bengal, Sikkim, Gujarat, Assam, Meghalaya – till July 4.
