Rainfall activity is likely to be above normal over the South Peninsula and Central India during the ongoing week ending on Wednesday next, with an extended range forecast by the India Meteorological Department (IMD) indicating light/ moderate scattered to fairly widespread rainfall with isolated heavy falls over the South Peninsula during the first half of the week.

This is also the phase when the latest low-pressure area persisting on Friday over the South-East Bay of Bengal and East Equatorial Indian Ocean (a location to the extreme East on a straight line from Sri Lanka) will likely become ‘well-marked’ and sets off on a track towards Lanka in the next few days and impacts its coast, as well as that of Tamil Nadu in South India.

Above normal in South

The US National Centres for Environmental Prediction has persisted with the view that the system would be able to trigger moderate to heavy rain over the entire island nation of Sri Lanka during the week ending December 23 and propagating along the Tamil Nadu coast and progressively along the South Andhra Pradesh coast. 

The IMD says rainfall will be below normal over most parts of North-West, East and North-East India during the overlapping week ending on December 21. Meanwhile, during the post-monsoon (North-East monsoon over the South Peninsula) from October 1 to December 15, the country as a whole has received excess rainfall of 24 per cent, proving forecasts by various agencies. 

No major rain deficits

North-West India has recorded the maximum excess among the four individual geographical regions, with an excess of 96 per cent. It is followed at quite some distance by Central India with +28 per cent; South Peninsula with +11 per cent; and East and North-East India by +8 per cent. There is no major deficit save in coastal Karnataka, West Rajasthan and Saurashtra and Kutch, so far during the period. 

The IMD said in its outlook on Friday that minimum (night) temperatures are expected to fall over North-West India, Central India and East India, as the autumn slowly gives into winter. Snowfall in the higher reaches of the Himalayas and a fog cover unfolding from time-to-time across the stretch have already signalled the slow but sure drift into the Northern Hemisphere winter. 

Autumn giving in to winter

Shallow to moderate fog may hang over East and North-East India for the next few days as moisture from the last western disturbance that crossed the region lingers. There’s apparently a break in the movement of warm western disturbances for the foreseeable future, which means that there would be no cloud cover to act as a buffer against the cold seeping in from the North-West. 

This will, in turn, lower the minimum (night) temperatures, since the colder and denser air wafting across the international border will sink in to the ground. The cooler air is expected progressively to filter into Gujarat to the West and Maharashtra to the South in the absence of western disturbances. The IMD sees no big prospect of change in weather over the next four to five days. 

Related Topics