Thiruvananthapuram/New Delhi, May 14:
The South-West monsoon is likely to set in over Kerala two days early on May 30, India Met Department announced this evening.
The
prediction of the onset data assumes an error margin of plus or minus
four days. The normal onset date is June 1. Importantly, the agency
noted that the El Nino weather condition – a heating of ocean water in
the eastern and central Pacific Ocean – is strengthening. Several
international Met agencies in the US, Australia and Japan, have forecast
a 70 per cent probability of an El Nino event in 2015.
The
phenomenon is a cause for concern since it could lead to a second
consecutive season of below-normal rainfall leading to drought
conditions.
“El Nino conditions are concerning, they
have been prevailing since March and is likely to strengthen during the
monsoon and post-monsoon season. We will update the analysis for our
forecast in June,” said an IMD official.
‘No El Nino worry’
While
its prediction for the date of the monsoon onset – May 27 with the same
margin of error - is similar to the Met Department’s, private weather
forecasting agency Skymet disputed the assertion of an evolving El Nino.
The
agency had earlier predicted that rainfall in 2015 would be 102 per
cent of the Long Period Average (LPA) with an 82 per cent probability of
normal-to-above-normal showers. It varied with IMD’s forecast of the
South-West monsoon being below normal at 93 per cent of LPA, the average
rainfall India received between 1951 and 2000 which stands at 89 cm.
“Analysing
drought patterns through this and the last century, the year after the
phenomenon is established has no drought. Last year, rainfall was 12 per
cent below the LPA, it’s classified as a mild meteorological drought
but the Government denied it. Our contention is that the El Nino episode
is devolving this year,” said Jatin Singh, CEO, Skymet.
Skymet
collates its information through 2,500 weather stations and satellite
data and its computing model comprising 124 programs predicts no impact
on the coming monsoon.
“The monsoon will be decent
through June and will climb across the country. Our El Nino theorising
is converging with our computing. The region is cooling off over the
next 5-6 months,” said Singh.
Both agencies agreed
that Indian Ocean Dipole (IOD) conditions, which also impact the monsoon
in conjuction with the El Nino, were neutral.
Andaman onset
Earlier,
the Met said that conditions are becoming favourable for the onset of
monsoon at the extreme outpost of Andaman and Nicobar Islands over the
next four days.
The islands at the extreme south-east are the first port of call for the monsoon.
Sri Lanka will be next, in a matter of 8-10 days followed by South West coast of India (Kerala) immediately thereafter.
The
Thailand Meteorological Department said in its assessment that the
winds are already south-westerly over the Andaman Sea clocking between
16- to 30 km/hr.
The wind speeds need to stabilise to around 30 km/hr for the monsoon onset to be declared in these parts.
‘Low’ delayed
Over Sri Lanka, the surface wind was variable in direction (or calm) and the speed was much slower at about 5- to 20 km/hr.
The wind was from the sea during day time along the coastal areas.
But the positive signals here included high atmospheric water vapour content.
Atmospheric pressure values over are also below monthly averages (making it easier for monsoon winds to blow in).
These
announcements came on a day when India Met also withdrew the outlook
for a low-pressure area over Lakshadweep (Arabian Sea).
Buzz in bay
Satellite
maps showed a high-pressure area (dry air from the Arab desert)
settling in over north and central Arabian Sea and delaying the genesis
of the ‘low’ even as the parent cyclonic circulation persisted.
According to the US National Centres for Environmental Prediction, the
‘low’ could materialise but would be pushed into the outer seas
initially by north-easterly winds from the high-pressure area.
Meanwhile,
the European Centre for Medium-Range Forecasts persisted with its
outlook for a buzz developing over southwest Bay of Bengal off Tamil
Nadu coast from this weekend.
It will undergo
calibrated growth in the warm central Bay of Bengal and even could end
up as a tropical cyclone over West Bengal coast with a projected
landfall on May 23-24, the European agency said.
If
this were to happen, the onset of monsoon is also likely to happen over
the Kerala coast since the system is projected to travel all the way
from off the south-east peninsula to the north-east.
Pacific typhoon
The
benign presence of a another strong typhoon building sufficiently far
away into the central Pacific and going further away south of the Korean
peninsula would also help pull in the monsoon as a whole.
The
European Centre saw cross-equatorial flows of monsoon off the Somali
coast picking up after Sunday, leading up to the initiation of the
disturbance in Bay of Bengal.
Source: BusinessLine
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