Southern Kerala, adjoining southern Tamil Nadu and coastal Karnataka will record a bulk of rainfall expected to be generated over the next fortnight as the North-East Monsoon envelops the peninsula.
The US National Centres for Environmental Prediction saw below normal rain for north coastal Tamil Nadu (covering Chennai) and adjoining south coastal Andhra Pradesh during this period.
CYCLONIC WHIRL
A cyclonic circulation has developed over south-west Bay of Bengal off Tamil Nadu/Sri Lanka coast on Wednesday.
This is forecast to head west-northwest to hit South Tamil Nadu coast and move onward into Kerala/coastal Karnataka.
This is what will bring the rain to the region as forecast by the US agency.
A US military forecast went on to corroborate this saying that coastal waters off Kerala may witness sustained buzz during this period. It went on to suggest that it could cause the formation of a cyclonic circulation in the south-east Arabian Sea and produce rain for Kerala, before moving away from the coast and into the central Arabian Sea.
RISE IN ACTIVITY
The US National Centres for Environmental Prediction saw probability of above-normal rainfall also for entire Gujarat during the fortnight under reference.
There will be a marked rise in rain activity over the southern peninsula from October 24 to November 1 as rain-bearing easterly waves cross in from South-East Bay of Bengal and land up over the East Coast.
These waves carry their rain-head upfront and dump their moisture on impacting land.
The waves have in the past developed storm heads, transforming themselves to full-fledged cyclones.
This is more or less akin to the manner in which very severe cyclone Phailin developed as a small disturbance in South China Sea off Thailand last week.
PHAILIN TRACK
It was born on October 4, moved slowly west and then north-westward through the Bay of Bengal next door, reaching tropical cyclone strength on October 9.
At one point in its lifecycle, Cyclone Phailin was the strongest storm ever measured over the Indian Ocean, according to a review by the Australian Bureau of Meteorology.
Phailin made landfall near Gopalpur in Odisha on October 12 at Category 4 strength (just below class-topping Category 5 on the Saffir-Simpson scale of storm intensity).