La Nina may decay only to rebound later this year, say Japanese experts

Japanese researchers have lately agreed that the currently strong La Nina phenomenon in the equatorial and east Pacific could weaken quickly over the next few months but would rebound later this year.

This is the only change in the outlook of researchers at the Tokyo-based Research Institute for Global Change (RIGC) who had until now projected that the La Nina would continue unhindered through the year and into the next.

REBOUND LATER

The latest outlook made available to Business Line on Monday says that the cold La Nina condition would rebound in late 2011 and persist up to early 2012.

This would mean that the Indian monsoon would co-exist with neutral (neither El Nino nor La Nina) conditions in the east Pacific around the time the four-month season gets under way in June later this year.

The monsoon had ended up just above normal last year on the back of a strong concurrent La Nina, but which also set off flooding conditions in parts of the country as well as in Pakistan.

Associated with the strong La Nina influence, below-normal surface air temperature and above-normal precipitation would continue in Australia, Brazil, and southern Africa during the next few months, the RIGC said.

‘ACTIVE’ WESTERLY

Southeastern China, the US, and southwestern Japan would likely witness warmer-than-normal and dry climate during the spring-summer seasons.

Meanwhile, back home, the prevailing ‘active’ westerly disturbance would cause heavy to very heavy rain or snowfall at isolated places over Jammu and Kashmir and Himachal Pradesh on Tuesday as well.

An evening outlook issued by India Meteorological Department (IMD) on Monday said that heavy to very heavy rain or snowfall would also occur at isolated places over Uttarakhand on both Tuesday and Wednesday.

Isolated thunder squalls and/or hail may break out over Rajasthan, Haryana and Uttar Pradesh during this period.

WIDESPREAD RAIN

The 24 hours ending on Monday afternoon saw widespread rain or snow being reported from Jammu and Kashmir and Himachal Pradesh and fairly widespread over Uttarakhand.

Fairly widespread rain or thundershowers occurred over west Rajasthan, scattered over Punjab and Haryana and isolated over east Rajasthan during this period.

Satellite imagery showed convective clouds persisting over parts of Jammu and Kashmir and Uttarakhand.

The active western disturbance would continue to affect western Himalayan region and plains of northwest India for three more days and later the Gangetic plains and the Northeastern States, the IMD said.

EASTERLY RAINS

An outlook valid until Sunday agreed with that of international models that scattered rain or thundershowers would occur over Kerala, Tamil Nadu, Andhra Pradesh, Orissa and the Northeastern States.

Model forecasts, including by the Global Forecast System of IMD, sees a fresh intervening western disturbance hitting the hills of the northwest around Sunday, to add a sting to the tail of the prevailing ‘active’ westerly system.

This is presumably what would trigger easterly rains along the southeast coast along Andhra Pradesh, Tamil Nadu and peninsular south towards the weekend. An anticipated weather system from the Bay of Bengal may just aid the cause, forecast outlook suggested.