Thiruvananthapuram, Sept 14
The rain belt in the extreme south peninsula moved slightly north leaving southern Kerala and Tamil Nadu more or less clear, but became concentrated over north Kerala, coastal and north interior Karnataka, coastal Andhra Pradesh, Telangana and Rayalseema on Thursday.
It merely kept pace with the northward progression of the global band of `low' packed in the Inter Tropical Convergence Zone (ITCZ), said Dr Akhilesh Gupta of the Department of Science and Technology.
The east-west shear zone also continues to be active over South India, except the extreme south.
This will be enough to sustain the ongoing rainfall activity in the region at least for the next three days.
Meanwhile, the India Meteorological Department said the outlook for the next `low' in the Bay of Bengal basin has been deferred until Saturday. A preparatory cyclonic circulation has been persisting over the past day or two.
The National Centre for Medium Range Weather Forecasting (NCMRWF) said the circulation located over the west central Bay, and off the Andhra Pradesh and neighbouring Tamil Nadu coasts, is likely to concentrate further and move in west-northwest direction.
NOT A MUST
As long as the shear zone is active in the region, it can do with or without a `low', said Dr Gupta. There could be one or more circulation embedded into this zone.
These circulations thrive in the larger shear zone and it is possible that one of these may go to set up a `low' prospectively.
The NCMRWF has forecast that the system will churn to bring widespread rainfall with isolated heavy to very heavy showers over coastal Andhra Pradesh, Telangana, Rayalseema and coastal Tamil Nadu in the next three days.
RAINS TO THRIVE
Fairly widespread rainfall with isolated heavy to very heavy falls is also likely to continue over the North-Eastern States, sub-Himalayan West Bengal, Sikkim and the Andaman and Nicobar Islands in the next two days.
A western disturbance is currently moving across the hilly regions of North-West India and adjoining plains, causing scattered rainfall over the region.
Under its influence, rain activity is likely to sustain over the region during the next 24-36 hours.Isolated heavy to very heavy falls are likely over the North-Eastern States, sub-Himalayan West Bengal, Sikkim, coastal Andhra Pradesh, south Konkan, Goa, coastal Karnataka and the Andaman and Nicobar Islands.