Hills and plains of north-west India are getting battered by an ‘intense western disturbance’ coming in from across the border.

The India Meteorological Department (IMD) has warned of heavy to very heavy rainfall/snowfall, at times extremely heavy, over Jammu and Kashmir and Himachal Pradesh.

2-DAY WARNING

The warning is valid for at least next two days, the IMD said in its evening bulletin on Monday.

A similar warning is also in place for Uttarakhand. Besides, hailstorm may rough up Uttarakhand and Uttar Pradesh. Adjoining north Haryana and Himachal Pradesh too may get clobbered by hailstorm during next two days.

Squally winds would rip through Punjab, Haryana, Delhi, north Rajasthan and west Uttar Pradesh on Tuesday.

All this happens as the intense low-pressure wave makes a forced entry from overnight perch over north Pakistan/Afghanistan.

DESERT ‘LOW’

The scenario will transform entirely with the formation of a low-pressure area over the deserts of west Rajasthan by Tuesday.

This may sound slightly far-fetched but weather-setting low-pressure areas can also form over Rajasthan when typical meteorological factors converge.

Lying in wait already is a cyclonic circulation, induced by the sheer size and scale of the western disturbance, with ‘limbs’ probing the Arabian Sea and Bay of Bengal.

Winds associated with the disturbance will fan into both the peninsular oceans to mop up moisture.

FOG, COLD OFF

The moisture will get deposited as rain (in plains) or snow (over hills) in Northwest India depending on the type of geography. The upshot of these conditions is that foggy conditions and extreme cold would get blown away for next two or three days. Western disturbances feature ‘weather engines’ upfront with moisture steaming as air rises up as in cyclonic circulation. This will warm up the atmosphere, and formation of clouds will trap warmth from escaping into space.

Minimum (night) temperatures also look up in the bargain, and IMD has mentioned it in Monday’s bulletin.

>vinson.kurian@thehindu.co.in