Activity will return to the Bay almost in tandem with the onset of monsoon over Kerala, but it will have shifted north into the central parts.
Thiruvananthapuram, May 20
The Arabian Sea arm of the monsoon has fascinated weather watchers with its fleet-footed nature over the past two days in dire contrast to its Bay of Bengal counterpart, which is stagnating after the initial flourish.
The Bay of Bengal arm has failed to make any further advance during the last 24 hours, says a forecast by the National Centre for Medium Range Weather Forecasting (NCMRWF). Prediction suggests its strength may sustain for the next 48 hours but only decrease thereafter, leading to reduction in associated cloudiness and rainfall activity, Dr Akhilesh Gupta of NCMRWF told
But concurrently, things are seen revving up above the ocean basin to the west of the peninsula with a band of helpful westerly winds gaining conspicuously in strength. So strong as to blow into the Bay in the east and heave the region of maximum cloudiness to Myanmar and further into the northeast, said Dr Gupta.
Activity will return to the Bay almost in tandem with the onset of monsoon over Kerala, but it will have shifted north into the central parts, unlike over the southeast and south when the season started off.
Meanwhile, model predictions continue to indicate strengthening of the lower level wind flow over South West Arabian Sea and the Indian Ocean region south of the mainland on Wednesday and Thursday. Large-scale cloudiness will begin to form and rains gain in intensity over the South-Central and South East Arabian Sea in conjunction. Importantly, predictions also indicate gradual increase in sustained rainfall activity over Kerala and adjoining areas beginning from Thursday. The isolated pre-monsoon showers being experienced in the State will transform into sustained stream of showers. These can only mean the full-fledged onset of monsoon, given the contrasts in rainfall patterns and their timing. If this were to hold, the rains would have beaten the earliest official onset date (in a band of six) by at least two days.
Meanwhile, there are early indications of easterly winds penetrating the Gangetic Plains starting with West Bengal and Bihar by Friday. The east-west trough would also come into place by then, he said, smoothly replacing the monsoon-repelling north-south trough. This will be followed by a universal fall in day temperatures in the peninsula. These are all established weather features associated with the onset phase.