Atmospheric conditions favourable for the onset of the northeast monsoon

Kerala received widespread rainfall on Monday as the retreating southwest monsoon vigorously wagged its tail.

Heavy rainfall reports during the 24 hours ending at 8.30 a.m. on Monday came from Nedumbassery (11 cm), Parambikulam (9 cm), Kozha (8 cm), and Palakkad (7 cm).

Several centres spread across the districts of Palakkad, Wayanad, Ernakulam, Kottayam, Kollam, and Thiruvananthapuram received rainfall ranging between 6 cm and 3 cm on the gauge.

Director of the Thiruvananthapuram Meteorology Centre K. Santhosh on Monday said the State would continue to receive isolated heavy rainfall during the next three days.

The southwest monsoon was withdrawing and the atmospheric conditions were becoming more and more favourable for the onset of the northeast monsoon.

The India Meteorological Centre (IMD), in its bulletin for the day, said the flow of northeast monsoon currents would strengthen by Thursday/Friday to signal the onset of the season.

Mr. Santhosh said there was the possibility of intense rainfall in some parts of the State ahead of the onset of the northeast monsoon in the next three or four days since a ‘cumulonimbus’ cloud formation had taken shape over the area.

This is a phenomenon when rainclouds pile up tall and dense, towering up into the skies. Squally weather conditions are associated with it. The atmospheric instability it brings with it can cause intense thunder storms, according to him.

The IMD’s weather charts showed the presence of a slow churning upper air cyclonic circulation extending from 1.5 km to 3.1 km above the mean sea level over Tamil Nadu and also another cyclonic circulation at lower levels of the atmosphere over the Lakshadweep area on Monday. These systems are drawing heavy moisture from the seas on either side of the peninsula.