Explainer: Interplay of weather systems brought rain, thunderstorms
Rain with varying intensity accompanied by thunderstorms and gusty winds was experienced over many places in north-west India, including the Capital, over the past 24 hours, affecting normal life and disrupting flight schedules.
According to the India Meteorological Department (IMD), thunderstorms accompanied with squalls at a speed of 70-100 kmph prevailed at many places over Jammu and Kashmir, Ladakh, Delhi and Odisha, while winds with lower intensity, having speed of 40-70 kmph, prevailed at some places over Punjab, Himachal Pradesh, Uttarakhand Haryana, Chandigarh, Rajasthan, Vidarbha, Chhattisgarh, Kerala, interior Karnataka and coastal Andhra Pradesh.
Punjab received 9.9 mm of rainfall over the past 24 hours, while Haryana received 12 mm and HP received 2.8 mm. While the precipitation was massively surplus in Punjab and Haryana, it was below normal for this duration in HP.
Western disturbances
Hailstorms were also reported at isolated places over HP, Punjab, Haryana, Chandigarh, East Uttar Pradesh, Bihar, Madhya Pradesh, Vidarbha, Chhattisgarh, Telangana and south interior Karnataka.
The ongoing wet spell is attributed to the interplay of several weather systems prevailing in different parts of the country. A western disturbance as a cyclonic circulation lies over south Punjab and adjoining north Rajasthan and west Haryana in middle tropospheric levels.
An upper air cyclonic circulation lies over southwest Rajasthan in lower tropospheric levels along with an upper air cyclonic circulation over northeast Rajasthan and adjoining northwest Madhya Pradesh.
In addition, a trough, that is a linear area of low atmospheric pressure, is running from this cyclonic circulation to Bangladesh in lower tropospheric levels and another trough is running from Punjab to north Kerala in lower tropospheric levels.
Western disturbances play a crucial role in the weather conditions and are the major source of non-monsoon precipitation over northern and north-west India during summers and winters. These originate over the Mediterranean region and travel eastwards over the Indian sub-continent, getting their moisture from sources like the Mediterranean Sea, the Caspian Sea and the Black Sea.
Western disturbances are a common occurrence, with their frequency more in winters than summers.
