The Application Laboratory of the Japanese national weather forecaster Jamstec is the latest to predict a ‘wetter-than-normal’ condition for India and Pakistan in terms of the expected seasonally averaged rainfall this summer.

The April-based forecasts also suggest wetter climes for South-West Africa, the Philippines, Indochina, and western parts of the US. Most other partsof the globe would experience a warmer-than-normal conditions.

Positive IOD phase?

The Japanese agency also pointed to the possibility of a positive phase of the Indian Ocean Dipole (IOD) occurring later in summer in contrast to the negative IOD forecasts by other models, led by the Australian Bureau of Meteorology. The IOD is called the ‘Indian Nino’ since it mirrors the El Nino-La Nina phenomena in the Equatorial Pacific.

During its positive phase, the western basin of the Indian Ocean warms up relative to the East, and boosts a concurrent Indian monsoon. During a negative IOD, the East of the basin warms up but doesn’t help the monsoon. It starts around May or June, peaks in August-October and rapidly decays when the monsoon moves into the southern hemisphere.

The Japanese agency says North-West India alone would witness above normal temperatures in May. For the rest of the country it forecasts below normal temperatures ahead of the monsoon.

May would also bring normal to excess showers for the South and slightly less for the North. June, the first monsoon month, is expected to be cooler than normal for most of the country.

Wet June likely

Rainfall during June would likely be above normal mostly except for parts of interior South Peninsula. Kerala and Tamil Nadu may fall under the less-than-normal rainfall category.

In July, normally the rainiest month, the monsoon would be reasonably good for most parts of the country except in Rajasthan, Madhya Pradesh, Chhattisgarh, Uttar Pradesh and the North-East.

Good N-E monsoon?

Combined June-July-August outlook suggests heavy rain along the West Coast; a slight deficit in Haryana, Delhi, Uttar Pradesh, the East Coast and Karnataka. The North-Eastern States might witness a larger deficit.

September-October-November will see normal to slightly above normal rain in the South Peninsula and East-Central India, indicating a reasonably good North-East monsoon.

But below normal rainfall is forecast during this three-month period for Jammu & Kashmir, Punjab, Haryana, Uttarakhand, West Madhya Pradesh, South Uttar Pradesh and Bihar.

The Met Department downgraded the threat of swell waves for the West and East Coasts after the low-pressure system in the South Indian Ocean weakened. But a counterpart low-pressure system farther to the South-South-West (off Madagascar) was elevated to a named tropical storm, ‘Fakir,’ in a battle of wits witnessed over the past few days.