Heightened storm activity in the west Pacific will ramp up the intensity of the ongoing El Nino in the coming weeks.
A rare July cyclone in the southern hemisphere may add to the flare-up, according to the Australian Bureau of Meteorology.
PACIFIC CYCLONES
Cyclones (typhoons) in the northern hemisphere have anti-clockwise winds about them which boost the westerly flows over the Pacific waters.
In the southern hemisphere they are clock-wise, which deliver the same impact on the westerly flows over the Pacific.
What they combine to achieve is to trigger a strong reversal of trade winds near the Equator, the Australian Met said.
This will likely increase temperatures below the surface of the tropical Pacific Ocean, which may in turn raise sea-surface temperatures further in the coming months.
Thus, the El Nino, or warming of the equatorial and east Pacific, will strengthen, causing convection (cloud-building) and storminess to migrate away from Asia.
CRUCIAL MONTH
That this is timed to happen during July, the crucial month for monsoon rainfall for India, may not be the best bit of news for farmers.
Already, the monsoon has lulled after reaching a peak during early June, and weather models don’t see a major reversal of fortunes until the last week of July.
Weather watchers are scanning the Indian Ocean for signs of El Nino-like phenomenon of varied warming of the surface in the western and eastern basins.
Called the Indian Ocean Dipole (IOD), it can help the monsoon if the west of the ocean warms relative to the east, and vice-versa.
The first scenario is called the positive phase of the IOD, of which at least three models surveyed by the Australian Met are expected to happen during the next month or two.