Rain prediction for north India may not be good news amid flood crises

For the Capital, IMD has issued a yellow alert for moderate rain on Saturday, followed by light to moderate rain on Sunday

There’s unlikely to be any let up in the rains in north India anytime soon with the India Meteorological Department predicting heavy to very heavy rainfall over Uttarakhand, Himachal Pradesh and Uttar Pradesh for the next five days. The reason: another western disturbance, the second since June 1.

The bad news, especially for Delhi is that a lot of this rainfall will fall in catchment area of north Indian rivers, including the Yamuna. (HT)

The conditions suggest this, IMD explained: the western end of the monsoon trough is lying south of its normal position and the eastern end is lying north of its normal position; a western disturbance as a cyclonic circulation is lying over central Pakistan; another cyclonic circulation is lying over Haryana; a third cyclonic circulation over central Uttar Pradesh; and finally, a cyclonic circulation is also likely to form over northwest Bay of Bengal around Sunday (that could become a low pressure area early next week).

All these weather systems in the north mean more rain.

IMD defines heavy rain as rainfall between 64.5 mm and 115.5 mm in a 24-hour period and very heavy rain as that between 115.6 mm and 204.4 mm (any more and it is extremely heavy rain).

For the Capital, IMD has issued a yellow alert for moderate rain on Saturday, followed by light to moderate rain on Sunday.

“We will see major activity on Sunday itself, with rain expected from the afternoon. Moderate rain is expected in most parts of Delhi NCR till the early hours of Sunday. Another spell will then take place towards the second half of Sunday,” said Kuldeep Srivastava, scientist at IMD.

The good news for the rain-soaked north is that the western disturbance is a feeble one.

“There is a feeble western disturbance that is likely to impact the Western Himalayan region. In addition, we are expecting a cyclonic circulation to form over the Bay of Bengal around Sunday. The cyclonic circulation will help bring easterly winds. The interaction of these two systems may bring good rainfall to Uttarakhand, Himachal Pradesh, Uttar Pradesh around July 17, 18 and 19 but we are not expecting extremely heavy rainfall as yet over the region,” said Mahesh Palawat, Vice President, climate and meteorology at Skymet Weather.

The bad news, especially for Delhi is that a lot of this rainfall will fall in catchment area of north Indian rivers, including the Yamuna.

“It will definitely lead to an increase in flow of the rivers,” Palawat added.

HT reported on July 10 that an interaction between a western disturbance and the monsoon trough led to extremely heavy rainfall over Himachal Pradesh, Uttarakhand, Punjab and Haryana, causing landslides, flash floods, widespread damage to highways and other infrastructure. Floods in north India have led to death of over 100 people so far. Several parts of Delhi are seeing the worst floods in 45 years.

“Normally, such spells are not sufficient to lead to an increase in the water level, but we are likely to see waterlogging across the city as most drains are currently full and have no outlet. The stormwater drains could start spilling out, with them taking longer than normal to drain out,” said Bhim Singh Rawat, a Yamuna conservation activist and member of the South Asia Network on Dams, Rivers and People (SANDRP).

On Friday, parts of Delhi recorded light rain. Safdarjung, Delhi’s base weather station, recorded “trace” rainfall between 8.30am and 5.30pm on Friday. Lodhi Road, meanwhile, recorded 0.6mm during the same period, Palam 9.8mm, Jafarpur 1.5mm, Mungeshpur 3mm, Pitampura 3mm and Pusa 1mm. “Trace” rain was also recorded at Ridge and Ayanagar.

There is an orange warning for Uttarakhand on Saturday and Sunday. A red warning implies that local authorities need to take action to prevent disasters associated with extremely heavy rain; orange warning implies that authorities need to be prepared.

There is 1% excess rainfall over the country with 52% excess over northwest India; 21% deficiency over south peninsula; 19% deficiency over east and northeast India; and 2% excess over central India.