The low-pressure area over south-east Bay of Bengal has become less marked during the 24 hours ending Thursday morning but an associated upper air cyclonic circulation is moving slowly in a west-northwest direction.
Significant cooling
This should take the circulation towards the south Tamil Nadu and Sri Lanka coasts by Monday (November 30) and spark off some rain activity, the India Meteorological Department (IMD) said in an update on Thursday. Seawaters along the till-now productive stretch linking south-west Bay of Bengal to the south-east have cooled down significantly compared with those prevailing in the upper Bay of Bengal basin as well to the south.
This robbed the ‘low’ off the much-needed support at the ground level, reducing the moisture feed as well. International models have been indicating the progression of a cyclonic circulation towards the sub-continent, if not the ‘low.’
An update from the Chennai Met Centre said that isolated rainfall has been reported from Kerala, Tamil Nadu, coastal and south interior Karnataka during the 24 hours ending Thursday morning.
The north-east monsoon is currently in a weak phase with the southern peninsula slipping under a dry spell over the last couple of days. Weather models, though, suggest that isolated rain or thundershower activity would continue.
The outlook from the Chennai Met Centre has said that isolated rain or thundershowers are likely over Tamil Nadu, Puducherry, Kerala, Lakshadweep, coastal and south interior Karnataka over the next two days.
The satellite cloud imagery put out by the IMD showed convective clouds over parts of south Arabian Sea.
According to the US National Centres for Environmental Prediction (NCEP), the rain-or-thundershower regime over the southern peninsula would last until December 3 with slightly concentrated wet regime over the Tamil Nadu coast.
December 4 to 12 would witness a renewed push of rains from the south and south-east ahead of the next wet phase of the Madden-Julian Oscillation (MJO) wave that travels in the upper levels from west to east.
The wave provides guidance for weather to play out over ground by helping set off convection, cloud-building and precipitation. The alternating suppressed rainfall phase (dry phase) of the MJO event is currently in operation over the peninsular seas.
Towards the north, minimum temperatures were below normal over many parts of east and northwest India and the North-eastern States on Thursday, an IMD update said.
The lowest minimum temperature of 5.0 deg Celsius was recorded at Sarsawa in Uttar Pradesh as colder north-westerly winds continued to blow into the country.
Outlook for the next two days said that minimum temperatures are likely to fall further over parts of central and east India and plains of northwest India.
A fresh western disturbance is likely to affect western Himalayan region from Sunday. The arrival phase would reverse the dip in mercury for a while, but would again turn colder after the westerly system moves away to the east.
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