The IMD has a set criterion for declaring the onset of SW monsoon over Kerala that are dependent on factors such as rainfall, wind field and Outgoing Longwave Radiation (OLR)….reports Asian Lite News
In what can be termed as a countdown to the onset of southwest monsoon over Kerala, the India Meteorological Department (IMD) on Tuesday said conditions are favourable for its further advance during the next 48 hours.
Earlier, the IMD had announced the onset date of southwest (SW) Monsoon over Kerala on May 27 with a model error margin of plus/minus four days, ahead of the regular date of June 1. Currently the northern limit lies to the south of Sri Lanka.
“Conditions are favourable for further advance of Southwest Monsoon over some parts of southwest Arabian Sea, some more parts of southeast Arabian Sea, Maldives & Comorin area, south & east-central Bay of Bengal and some parts of northeast Bay of Bengal during the next 48 hours,” the IMD said.
Last week, the IMD had expressed the possibility of the SW monsoon hitting the Kerala shores on May 25. Tuesday’s announcement of advance till Comorin area — Kanyakumari shores — would mean the SW monsoon would be nearer to Kerala’s southern tip and provided other criterions are fulfilled, IMD would be able to declare the onset.
The IMD has a set criterion for declaring the onset of SW monsoon over Kerala that are dependent on factors such as rainfall, wind field and Outgoing Longwave Radiation (OLR).
First, if after May 10, 60 per cent of the designated 14 stations enlisted in Kerala report rainfall of 2.5 mm or more for two consecutive days, the onset over Kerala can be declared on the second day, provided the other two criteria — with identified/established specifications for wind field and Outgoing Longwave Radiation (OLR) — are also in concurrence.
The 14 stations in Kerala are: Minicoy, Amini, Thiruvananthapuram, Punalur, Kollam, Allapuzha, Kottayam, Kochi, Thrissur, Kozhikode, Thalassery, Kannur, Kudulu and Mangalore.
Prior to this, much before its normal date of May 22, the monsoon had reached and crossed Andaman & Nicobar Islands on May 15 itself.
