The Hindu Business Line : Well marked ‘low’ may prolong rains

Thiruvananthapuram, March 22 Friday’s ‘low’ over southeast Arabian Sea has undergone a round of intensification to become well-marked on Saturday and is expected to prolong the heavy to very heavy rainfall activity over Kerala and Tamil Nadu.

According to the US Joint Typhoon Warning Centre (JTWC), the area of widespread but highly decentralised convection was located off the south Kerala coast. The satellite imagery showed broad low-to-mid level cyclonic turning. Winds speeding up to 15 knots wound down into the system with still faster winds riding the periphery.

WIND SHEAR

The low to moderate vertical wind shear and proximity to land would curtail further development of the system, and the JTWC assessed as ‘poor’ chances of formation of development of a significant tropical cyclone within the next 24 hours.

The JTWC does not recognise the ‘well marked’ status for a ‘low’; according to it, a ‘low’ could grow next as a ‘tropical depression’ or a ‘tropical storm.’ This, however, is ruled out for the next 24 hours at least, it said in its bulletin.

The India Meteorological Department (IMD) said in its update on Saturday that the well marked ‘low’ would continue to trigger widespread rainfall with isolated heavy to very heavy falls over Tamil Nadu, Kerala, coastal and south interior Karnataka during the next two days.

Fairly widespread rainfall with isolated heavy falls is also likely over Konkan, Goa, Andhra Pradesh and north interior Karnataka, with the rain belt getting steered to north-northeast by the westerlies blowing across the central and north Arabian Sea. Rain or thundershowers are likely at most places over Kerala, coastal and south interior Karnataka and south Tamil Nadu.

A special forecast issued separately warned of isolated heavy to very heavy falls over Tamil Nadu, Kerala, coastal and south interior Karnataka. According to the Extended Forecast System of the US Fleet Numerical Meteorology and Oceanography Centre, the rampaging rain belt would pivot around a base, around central Kerala from Sunday onwards, and propel itself into the northeast straddling central and north Tamil Nadu, coastal Andhra Pradesh and beyond.

But the rain-belt is shown to get broken up trunk-ward by Wednesday, with the Tamil Nadu stretch getting detached from the northeast. This would help clear up the coastal region over the next few days but indications are that another ‘low’ could show up by month-end, this time over the southwest Bay of Bengal and perilously close to the Tamil Nadu coast.