Western Disturbances Control Weather over Indian Sub Continent

Weather Update

Weather bloggers from South India are used to seeing a train of pulses moving into Bay of Bengal from South China Sea during Northeast Monsoon time. Northeast Monsoon 2021 during the month of November saw these train of pulses triggering near continuous rains over coastal Tamil Nadu. The Yin & Yang of Weather now has an opportunity to showcase the otherside with a string of Western Disturbances influencing weather over the Indian Subcontinent.

It is almost like the Pandemic that has forced people to lead their normal lives in short spells amidst spells of waves across the globe, normal winter conditions over Indian Sub Continent seems to be happening in short spells amidst a train of Western Disturbances that move across Indian Sub Continent in regular frequency. Take the current scene over Indian Sub Continent which already has a Western Disturbance influencing weather over North India while another, fairly intense one, waiting over Iran & adjoining region to enter into the Indian Sub Continent in a couple of days time while a third one is getting its genesis organized over the Mediterranean Sea to move in next week.

While in normal context down south our weather is not influenced by the Western Disturbances as more often than not it is North India and under some conditions the northern parts of Deccan Plateau see rains / hailstorms happen due to Western Disturbances. But like last week occasionally we have an interplay between Mid Level Westerlies & Lower Level Easterlies creating unstable atmospheric conditions over Peninsular India bringing rains. This phenomenon is more pronounced during the La Nina years.

The days preceding Pongal might see another interaction though weather models are not expecting any major rainfall event over Tamil Nadu possibly due to higher weightage towards a stronger circulation moving in a NE directrion under the influence of semi permanent ridge bringing drier NE winds along with it.

Nevertheless considering it is the harvest window and even 3 to 5 cms of rains may be damaging for the mature Paddy crop awaiting harvest it might be prudent for farmers who have their crops in the harvest window to complete their harvest without any delay rather than waiting for the traditional window right after Pongal festivities.