Laila might advance onset of monsoon: IMD

Jisha Surya
First Published : 22 May 2010

THIRUVANANTHAPURAM: ‘Will Laila do an Aila act?’ This question started bothering weather experts across the country when the cyclone first developed as a deep depression in the Bay of Bengal. While the India Meteorological Department (IMD) believes that Laila would be ‘harmless’ unlike Aila which destroyed the monsoon build-up last year, some experts point to another unknown and unnamed cyclone, which poses a possible threat to the monsoon.
C K Rajan, professor in-charge, Chair for Climate and Environmental Changes, SCMS, said: “Another cyclone that developed in the Bay of Bengal has moved to the Somali coast. This cyclone is causing heavy rains on the Somali coast, developing a high pressure area in the northern hemisphere. This will weaken the cross equatorial flow.’’
The cross equatorial flow is the movement of moisture-rich wind from high pressure area in the southern hemisphere to the low pressure area in the north.
If a high pressure region develops in the northern hemisphere, the cross equatorial flow will become weak which will, in turn, affect the intensity of rain.
However, the officials at the Met Department here said they are not making an analysis of the phenomenon on the Somali coast.
“Except for the new system that has moved to the Somali coast, all other factors are favourable for the onset of monsoon. In fact, the arrival of Laila will strengthen the cross equatorial flow,’’ Rajan said.
Comparing Laila with Aila, Rajan said: “Aila affected the monsoon build-up in the Bay of Bengal as it developed after the onset of monsoon. Whereas Laila came a little early and it is expected to turn in a positive way.
''Only 4 percent of the wind will contain moisture. So anything that strengthens the flow of cross equatorial current could increase the intensity of rain.’’
IMD (Thiruvananthapuram) Director K.Santhosh said the arrival of Laila might advance the onset of monsoon.
He, however, admitted that the IMD did not make record of the phenomenon on the Somali coast.
MONSOON NEARING
T’Puram: Whether to thank Laila or not, the current situations indicate the earlier onset of monsoon. IMD Director K.Santhosh said: “The monsoon has already hit Sri Lanka and the Maldives much before the due date, May 25. As per indications, conditions are favourable for an early arrival of monsoon.’’
 Regarding Laila, he said, the wind pattern is favouring the advent of monsoon.
“As the cyclone move more towards north-east, it favours the south-westerly wind. This wind pattern favours the advancement of  monsoon,’’ he said.
Heavy rain, which is an impact of cyclone Laila, is likely to occur at isolated places in the state during the next 48 hours. “Rain will last for another 48 hours,’’ Santhosh said.
“A warning has been issued against fishermen venturing into the sea as there is strong onshore winds, with a speed of 45 to 55 kmph, from northwesterly direction,’’ he added.