Northeast monsoon for the South Peninsula is likely to enter a lenient phase. Weather activity will go rather weak across most of the region, with only few exceptions. The trigger systems of monsoon current will remain far to the south of their normal position and therefore, long spell of sparse activity is expected. The interiors of Peninsular India will be further leaner than the coastal belt.
Currently, South Peninsula has a seasonal shortfall of about 15% rainfall. The hardest hit are Telangana and North Interior Karnataka with respective deficiency of 56% and 64%. However, both these sub divisions do not form a part of the northeast monsoon region. Out of five meteorological sub-divisions of northeast monsoon, Kerala and Tamil Nadu are placed reasonably well. This is the main rainy season for Tamil Nadu and the state has a marginal shortfall of 3%. Kerala is surplus with 22% rainfall. The other three regions comprising of Coastal Andhra Pradesh, Rayalaseema and South Interior Karnataka are down with 16%, 28% and 26% rainfall.
Easterly wave, easterly trough and cyclonic circulations embedded in the main stream of northeasterly winds are the trigger for monsoon. All these weather systems have a normal track from east to west, moving in the close proximity of Sri Lanka, southwest Bay of Bengal, Palk Strait and Lakshadweep, at this time of the year. However, most of these disturbances are tracking well south, moving across low equatorial region, Comorin and Maldives area, keeping safe distance from the mainland India. Earlier, tropical cyclone Michaung, as such, disturbed the monsoon pattern. The combined influence will leave the southern parts, fairly short of normal activity and that too for longer than expected.
The latest weather system as a well marked cyclonic circulation will reach south of Sri Lanka on 15th December, Comorin area on 16th Dec and Maldives and surrounding region on 17thDec 2023. The passage of this feature will trigger scattered rain and thundershowers over southern parts of Tamil Nadu and Kerala on 16th and 17thDec. Other than this, the weather activity will remain absolutely weak over most areas impacted by the northeast monsoon. Accordingly, the rain deficit sub divisions will further increase their margins. As such, the level of activity starts taking a back seat towards 3rd and 4th week of December. The track of northeast monsoon has a tendency to track lower, mostly over parts of Sri Lanka and Maldives. Any large deficiency, if accrued, will find it difficult to catch up during the remaining duration of northeast monsoon.