Isolated heavy rainIsolated heavy rain is expected over Tamil Nadu, Puducherry and Karaikal for three days; South Interior Karnataka for four days; and Kerala and Mahe for four days from Wednesday.
Kerala and Mahe could receive such showers for three days, and Coastal Karnataka today and South Interior Karnataka and Telangana today and again towards the weekend.
Widespread showers seenThe rain could become fairly widespread to widespread over Kerala and Mahe for three days from Thursday; Coastal Karnataka for five days from Tuesday; and South Interior Karnataka for three days.
Tamil Nadu, Puducherry and Karaikal could see these conditions for four days, while Kerala and Mahe may experience gusty winds for three days.
North and South Interior Karnataka could see gusty conditions for two days; and Coastal Andhra Pradesh, Yanam and Rayalaseema for four days.
With just three days left in the south-west monsoon season, the Bay of Bengal has stirred into another bout of activity, with an incoming weather pulse from Thailand intensifying rapidly over the weekend into a depression by Monday morning.
The development had been flagged by businessline eight days ago, based on India Meteorological Department (IMD) numerical model guidance, which had indicated the potential for the system to emerge over the Bay and intensify.
Another deep depression
The latest depression, however, is unlikely to turn towards the Indian coast. The IMD said it could strengthen further into a deep depression by this (Monday) evening and move along and off the Myanmar coast towards north-east and adjoining Bangladesh coast over next three days. The depression lay over the north Andaman Sea and adjoining Myanmar coast, about 590 km east-north-east of Mayabandar in the Andaman Islands.
The Bay system’s evolution comes as the south-west monsoon steadily retreats from the mainland, clearing the stage for seasonal transition to the north-east monsoon. The withdrawal line on Monday passed through Gurdaspur; Chandigarh; Muzaffarnagar; Aligarh; Dholpur; Udaipur; Deesa; and Naliya, marking further retreat across Punjab; Chandigarh-Haryana-Delhi; Uttar Pradesh; Rajasthan; and Gujarat.
Residual ‘low’ weakens
A residual low-pressure area over east Uttar Pradesh, remnant of the preceding deep depression, has weakened as withdrawal accelerated across northern India. The transition is expected to become evident first over the Arabian Sea, where south-westerly winds ay give way to easterlies by around October 7. The Bay could take slightly longer to fall into step, with short-to medium-range guidance pointing to a shift around October 12.
That change in wind regime could open the door to a fresh spell of rain and thunderstorms across larger Peninsular India and the South Peninsula, even as the south-west monsoon formally winds down. The IMD outlook points to a broadening spell of rain and thunderstorms from the middle of the week.
Isolated heavy rain
Isolated heavy rain is expected over Tamil Nadu, Puducherry and Karaikal for three days; South Interior Karnataka for four days; and Kerala and Mahe for four days from Wednesday. Rainfall is likely to be isolated to scattered over Coastal Andhra Pradesh and Yanam; Lakshadweep; North Interior Karnataka; Rayalaseema; and Tamil Nadu, Puducherry and Karaikal for next six days. Kerala and Mahe could receive such showers for three days, and Coastal Karnataka today and South Interior Karnataka and Telangana today and again towards the weekend.
Widespread showers seen
The rain could become fairly widespread to widespread over Kerala and Mahe for three days from Thursday; Coastal Karnataka for five days from Tuesday; and South Interior Karnataka for three days. Thunderstorms, lightning and gusty winds are also expected to accompany the transition. Tamil Nadu, Puducherry and Karaikal could see these conditions for four days, while Kerala and Mahe may experience gusty winds for three days. North and South Interior Karnataka could see gusty conditions for two days; and Coastal Andhra Pradesh, Yanam and Rayalaseema for four days. Telangana is also likely to experience gusty winds on Monday.
Rain deficit narrows
The departing monsoon has nevertheless managed to make some late gains in the national rainfall balance. The track of the ‘low’ from the Bay northwards to east Uttar Pradesh helped narrow the country’s cumulative rainfall deficit by about three percentage points from last week, to 12 per cent as of Sunday.
The South Peninsula, one of the most rain-starved regions through the season, saw its deficit improve to 23 per cent, while the North-East reduced its shortfall to 25 per cent. North-West India, with a six per cent deficit, and Central India, at two per cent, remained within the normal rainfall category. With only three days remaining in the official monsoon season, the East and Peninsular regions could still pick up some incremental rainfall before withdrawal, while the emerging wind reversal sets the stage for the next seasonal rain regime.
Published on September 28, 2026
