El Nino threat to monsoon recedes

NEW DELHI: The biggest threat to this year's monsoon seems to have receded. El Nino conditions that were building up in the Pacific have eased in the past month, prompting the Australian weather bureau to withdraw its El Nino 'alert' on Tuesday.

The bureau downgraded its outlook to El Nino 'watch', which means there's still a 50% chance of the weather event occurring this year. The 'alert' status corresponded to a 70% probability of an El Nino occurrence.

While that should be cause for cheer in India, the rest of the monsoon season isn't entirely threat-free. The Pacific continues to be warm, due to which a series of typhoons have been forming off south-east Asia. "Depending on which way a typhoon moves, it can aid or weaken the monsoon for a few days," said D Sivananda Pai, IMD's lead monsoon forecaster.

Another reason for slight concern is the persistence of warm waters in eastern Indian Ocean, which tends to take rainfall activity away from the Indian subcontinent. However, most climate models favour a return to normal temperature levels sometime next month.

But these are relatively minor worries compared to the threat of a full blown El Nino. The Australian Bureau of Meteorology, in an update, said despite the Pacific being primed for an El Nino for much of 2014, the atmospheric changes associated with the development have not taken place.

"As a result, some cooling has now taken place in the central and eastern tropical Pacific Ocean, with most of the key Nino regions returning to neutral values," it said.

El Nino is a periodic warming of ocean waters in the eastern and central equatorial Pacific, which drives changes in wind patterns impacting weather over a large part of the globe. El Nino generally leads to weak monsoon in India — the droughts in 2009, 2004 and 2002 being recent examples — although that's not always the case.

While most international weather agencies see the El Nino threat receding, the US's Climate Prediction Center still maintains a 70% chance of the event occurring during the monsoon season. But the consensus view seems to favour the occurrence of a mild El Nino later this year.

After a slight dip in activity over the last couple of days, the monsoon again picked up on Tuesday. The nationwide monsoon deficit reduced to 24% on the back of vigorous rains over east Rajasthan and good activity over west Uttar Pradesh and many parts of central and western India.

More rain is expected in these parts over the next two days. Meanwhile, another low pressure area is forming over the northwest Bay of Bengal. It would start moving inland in 48 hours, bringing another round of rains.