Out of these weather systems, the little known one is the trough, but it has a significant impact on the weather across many parts of the country. Troughs are lines where the atmospheric pressure is the lowest as compared to either sides. Also, here the winds turn around the most and become the opposite of what they were initially.
[yuzo_related]
During the pre-Monsoon and Monsoon season, troughs become a semi-permanent feature and most of the weather occurs due to these.
During the Monsoon season, it is the Monsoon trough which runs along the Indo-Gangetic plains. Another one is the off-shore trough off the West Coast. Meanwhile, the third runs along the valley of the North Eastern region of India.
As far as the pre-Monsoon season is concerned, the trough that runs across the interior Peninsular India is the sole trough which causes weather activity over the Peninsular region.
This has an oscillating nature and it keep shifting on either side. The oscillation occurs due to the prevalence of some weather system overboard the northern as well as the southern part of India. In fact, even though weather systems present over the oceans have an effect over the oscillation of this feature.
The Pre-Monsoon trough changes in orientation and extent due to which the weather activity also shifts. There are some small-scale circulations that form over some parts of the country where the heat content is on the highest side.
Nowadays, the trough is located over the Peninsula part of the country. A cyclonic circulation is over Jharkhand and adjoining North Chhattisgarh.
A trough is also extending across South Chhattisgarh, Telangana, Andhra Pradesh up to the Tamil Nadu region. Additionally, the anticyclone in the Bay of Bengal off Andhra Pradesh coast has been acting as a catalyst providing moisture to the trough.
Due to this, states right from Tamil Nadu, Andhra Pradesh, Odisha and West Bengal have witnessed good rainfall activity.
Moreover, peripherals of Telangana, Chhattisgarh and Jharkhand have also seen some rainfall activity. These rains are expected to switch into the first four days of April as well.
These weather activities will occur during the late afternoon hours for short duration which is a pre-Monsoon characteristic.
Please Note: Any information picked from here must be attributed to skymetweather.com