Avalanches hit several parts of Himachal Pradesh, heavy spells of snow blocked key roads in Jammu and Kashmir, and rainfall accompanied with lightning lashed parts of Uttar Pradesh and Punjab, as a western disturbance led to severe weather over parts of north India, the Himalayan region and neighbouring Pakistan, where at least 37 people died in rain-related incidents.

Weather experts said the current western disturbance (WD) is the most intense this season and will be followed by a second one that is likely to begin affecting the Western Himalayan region on the night of March 5 and leave a wet spell in the region till March 11.

“This is the same western disturbance that caused intense snowfall in Pakistan and associated casualties. It may have caused damage in Afghanistan also. This was the most intense WD of this season,” said M Mohapatra, director general of the India Meteorological Department (IMD).

At least 37 people died and 50 others were injured as heavy rains swept across Pakistan, collapsing houses and triggering landslides that blocked roads, particularly in the northwest, authorities in the neighbouring country said.

The system’s impact was stark for how far its effects were felt: In Uttar Pradesh, four deaths were reported in separate lightning strikes, a senior official said.

The IMD chief added that the impact was unlike what was seen earlier this year, when WDs typically hit the region. “There are some studies that show during El Nino years sub-tropical weather systems like WDs move to northern latitudes and do not affect the Indian region. We saw that in January. But since February, they have started affecting the Indian region also,” Mohapatra said.

A western disturbance is an extratropical storm that originates in the Mediterranean region. An area of reduced air pressure, this disturbance carries moisture from the Mediterranean and Caspian seas east, via the subtropical westerly jet stream. This brings rain and snow to Pakistan and northern India.

Earlier this season, there were fears over the lack of snow in the upper reaches of the Himalayas and triggered concern that a relatively dry winter could cause drought-like situations later in the year.

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Mohapatra said the snow recorded in the past couple of days were classified as “heavy to very heavy snow”. “All WDs are not of same intensity. This was one of those that caused severe weather,” Mohapatra added.

With moderate to heavy rain over north India over the past two days, maximum temperatures have dropped several notches over the plains including Delhi and the National Capital Region (NCR).

The India Meteorological Department (IMD) has forecast that the current wet spell is likely to continue with heavy rain or snow over Himachal Pradesh and Uttarakhand, and moderate thunderstorm or hailstorm over east Uttar Pradesh, Bihar and Sikkim.

“Now this system will move towards northeast of India. Intense rainfall/snowfall was mainly because of the western disturbance in combination with moisture incursion from Arabian Sea. With the passage of the WD, temperatures will drop marginally over north India. There is already a significant fall in day temperatures over many parts including Delhi-NCR. Two consecutive WDs are approaching so weather is expected to be pleasant, not very high,” Mohapatra added.

The rain and the hailstorms recorded over the weekend also triggered concerns that they may have hit crops close to maturity in Punjab and Haryana.

Elsewhere, it severely affected connectivity. An avalanche hit a village in the Lahaul and Spiti district of Himachal Pradesh early on Sunday, obstructing the flow of Chenab and triggering an alert in the adjoining area, officials said. Over half a dozen avalanches and landslides led to the closure of over 500 roads, including five national highways.

In J&K, NHAI authorities stepped up efforts to resume traffic movement on Jammu-Srinagar national highway following improvement in weather. The 270-km highway is the only all-weather link connecting Kashmir with the rest of the country and was shut for a second day. Police shifted a large number of stranded passengers, including over 200 tourists, to safer places in Ramban district.