National

Weather Update: Hills On High Alert As Second Phase Of 'Break Monsoon' Trough Moves Northward

Scientifically, the monsoon trough is defined as an elongated low-pressure over the sea, also known as “heat low” starting from Pakistan to the head of the Bay of Bengal region (parts of Odisha, West Bengal, and Bangladesh). This is one of semi-permanent features of monsoon circulation according to IMD.

Representational Image
info_icon

After a devastating first phase of furious monsoon claiming hundreds of lives, the India Meteorological Department (IMD) speculates a fresh second phase of 'break monsoon' for several parts of India from the middle of this week.

According to the weather department, the second phase will be caused by the monsoon trough which is expected to shift its location towards north of its normal position during next two to three days. Several weather experts hold the  El Nino episode accountable for the weather phenomenon.

Scientifically, the monsoon trough is defined as an elongated low-pressure over the sea, also known as “heat low” starting from Pakistan to the head of the Bay of Bengal region (parts of Odisha, West Bengal, and Bangladesh). This is one of semi-permanent features of monsoon circulation according to IMD.

The dry spell for most parts of the country could start as early as Tuesday, another expert said, and last till the end of the month.

What does IMD say?

When asked about the expected second phase of monsoon, the IMD director general, M Mohapatra said, “With the shifting of the monsoon trough northward, we can expect subdued rainfall conditions in the plains particularly northwest India and peninsular India. We can also expect heavy rainfall activity over the Himalayan foothills including Uttarakhand, Himachal Pradesh, north Bihar, parts of northeast India. We cannot say immediately when the trough will shift to normal position because conditions are fluctuating,”

The hill states are on alert as they face another possible deluge.

Uttarakhand under high alert

As a pre-emptive measure to battle the second phase, the State Disaster Response Force (SDRF) of Uttarakhand has kept its personnel on standby with advanced equipment.

According to SDRF commandant Manikant Mishra, “After weather alerts, our total strength of 560 at 42 locations across the state remains on alert. We remain ready with the raft, deep diving equipment, sonar system, drones, thermal imaging cameras, and other advanced types of equipment to deal with any situation.”

“We ensure that our response time is minimal so that loss of human lives and damage to constructions can be reduced. We deploy our teams in flood-prone and landslide-prone areas to provide rescue and relief services in minimum time,” he later added.

Alert for Himachal Pradesh

Similar picture is visible in the neighbouring and the worst affected state of Himachal Pradesh where the director of the state disaster management authority DC Rana asserted that the government was prepared to deal with any situation.

“All concerned departments and officials have been put on alert. Rescue teams are prepared to move swiftly to flood and landslide prone areas. Men and machinery have been put in place to restore the roads in case of blockades,” he said.

Experts hold El Nino accountable

Several weather experts have concluded that the ongoing EL Nino, wjich is known to have a strong influence on the southwest monsoon in India, is primarily responsible for the current weather phenomenon.

Geologically, El Nino is characterised by an unusual warming of waters in the eastern equatorial Pacific, which has a high correlation with warmer summers and weaker monsoon rains in India.

“Moreover, the impact of El Nino on the atmosphere is clearly perceived now. During El Nino conditions, the sea surface temperatures over the eastern Pacific are very high, leading to high convection and clouding over South America but not so over the western Pacific and other parts. This also leads to a failure of the Indian summer monsoon. El Nino’s impact was felt over India only in August,” said M Rajeevan, former secretary, ministry of earth sciences.

“Monsoon trough is positioned northward for long time due to various reasons. One is a sinking motion or suppressed atmospheric conditions over central India which pushes the monsoon trough northwards. Sometimes western disturbance pulls it up. But the basic reason for long breaks is atmospheric dynamics associated with El Niño. El Niño impacts Indian monsoon through these long breaks,” he added.