More rain forecast for Tamil Nadu, Puducherry as pre-monsoon troughs look southward
A narrow corridor along the Tamil Nadu coast including Chennai (in dark and white hues) brought rain and thundershowers even as the hot regime (golden and red) ws pushed to the west and north-west over South India on Wednesday.
| Photo Credit:
www.meteologix.con/in
Moderate to heavy rainfall over Tamil Nadu, Puducherry and Karaikal on Wednesday is only a sample of things to come over the next few days as pre-monsoon troughs and circulations look to spin or look down their way along a corridor on eastern seaboard cutting across Odisha and Coastal Andhra Pradesh.
By Wednesday afternoon, a weather-making pre-monsoon trough had shifted axis to the west as it lay extended all the way down from south-west Rajasthan towards the narrow seas of Gulf of Mannar beyond the Tamil Nadu coast in deep south, India Meteorological Department (IMD) said.
More rain for South
IMD has forecast scattered light to moderate rainfall, thunderstorms, lightning and gusty winds for Tamil Nadu Puducherry, Karaikal, Coastal Andhra Pradesh, Yanam, Rayalaseema, Telangana and Karnataka for next five days. Scattered to fairly widespread light to moderate rainfall, thunderstorms, lightning and gusty winds are likely over Kerala and Mahe for four days.
An intense (powerful) western disturbance started affecting the hills and plains of North-West India (in dark hue) while the top heat belt shifted to East and East-Central India (golden and red) on Wednesday afternoon.
| Photo Credit: www.meteologix.com/in
Western disturbances
Southward-looking troughs are result of atmospheric instability created when cooler winds of western disturbances crossing Indo-Pakistan border run into prevailing air over sizzling North-West India and East India. Elongated troughs and localised circulations with lower pressure spring up over this prime weather belt to generate rain, thunderstorms, lighting and even hail.
Intense system in
On Wednesday an intense (powerful) western disturbance has started affecting hills of the Himalayas, a process that may sustain for next five days. Thunderstorms, lightning, gusty winds and hailstorms are forecast here on Friday and Saturday. Isolated heavy rainfall is likely over Jammu-Kashmir-Ladakh and Himachal Pradesh for two days.
Cyclonic circulations were seen perched over south-west Rajasthan, East Madhya Pradesh and east Assam. The circulation from south-west Rajasthan threw down a trough to Gulf of Mannar, while second trough ran east from East Madhya Pradesh to plains of West Bengal; and a third, from Sikkim to north Odisha, completing the pre-monsoon weather scheme of things.
Heavy rain in East
Isolated rainfall, thunderstorms, lightning and gusty winds are likely over plains of North-West India; and isolated dust storms/thunderstorms over West and East Rajasthan. It remains to be seen how many more troughs reach out south to sustain ongoing disturbed weather. Heavy rainfall is likely over Bihar and Assam and Meghalaya on Thursday and next three days.
Isolated hailstorms was forecast over Chhattisgarh and Vidarbha on Wednesday. Thunder squalls are likely over plains of West Bengal and Bihar. Scattered to fairly widespread light to moderate rainfall, thunderstorms, lightning and gusty winds are likely over North-East and East India during next five days. Isolated to scattered rainfall, thunderstorms, lightning and gusty winds are likely over Vidarbha and Chhattisgarh for three days.
Published on April 16, 2025
