New Delhi:An unusual weather phenomenon is unfolding across parts of India, Pakistan, and Afghanistan - bringing intense rainfall, thunderstorms, gusty winds, and even hailstorms in a month that usually kickstarts summer heat.

The rare event stands out not just in its timing, but also in its formation and shape.The phenomenon brings a perfectly linear low-pressure western disturbance extending a 1,000 kilometre rain band from Afghanistan through Pakistan and deep into India.

Usually, western disturbances are extratropical cyclones originating from Mediterranean lows, curving northeast and peaking in winter to bring snowfall and cold waves. In contrast, the current one is a straight trough, with weather patterns increasingly growing unpredictable lately.

The active western disturbance, an upper-air cyclonic circulation over northern Pakistan is driving widespread thunderstorms, gusty winds (40-80 kmph), isolated hailstorms, and light-to-moderate rainfall or snowfall across northwest India.

It has already triggered heavy to very heavy rain in the sub-Himalayan West Bengal and Sikkim, heavy showers in south Karnataka, Andhra Pradesh, Kerala, and Tamil Nadu, and hailstorms in multiple states.

The current western disturbance features a trough aloft in the middle and upper westerlies. This trough interacts with multiple lower-tropospheric cyclonic circulations over north Madhya Pradesh, east Uttar Pradesh, west Rajasthan, Haryana, northeast Assam, coastal Andhra, and interior Tamil Nadu-Kerala. 

Source:Ndtv