The Hindu Business Line : Monsoon posts 45% surplus in first 19 days

Thiruvananthapuram, June 19 The first 19 days of the monsoon have returned 45 per cent surplus in all-India area-weighted rainfall with 32 Met sub-divisions recording excess or normal rainfall and only five recording a deficit.

Kerala, Lakshadweep, Marathawada, Assam and Meghalaya found themselves in the red, posting deficits ranging from 30 per cent to 52 per cent according to statistics put out by the India Meteorological Department (IMD) on Wednesday.

Latest indications that the west coast along with Central India may witness an active wet spell from Saturday should help the cause of Kerala, Lakshadweep and Marathawada at the least.

The issue at stake would be whether the ‘surplus’ trend can carry into the crucial month of July. Varied forecasts available until the first week of July suggest the rains would be fairly well distributed all over the country.

SYSTEM WEAKENS

Meanwhile, the well-marked ‘low’ over Jharkhand weakened overnight into a conventional ‘low’ as the west-bound system left behind flooded tracts and stumbled upon a comparatively dry northeast Madhya Pradesh and adjoining east Uttar Pradesh on Thursday.

The weakening was occasioned by the snapping of the link with the moisture pool available on ground in the east. But the easterlies from the Bay of Bengal blowing in along the seasonal trough will pump in sufficient moisture to keep it alive and kicking.

The IMD has forecast widespread rainfall with isolated heavy to very heavy rainfall over Madhya Pradesh during the next two days. An upper air cyclonic circulation over Gangetic West Bengal will keep the wet spell going in the east with fairly widespread rainfall and isolated heavy falls being predicted for West Bengal, Sikkim and the North-East.

REPEAT ‘LOW’

On Thursday, the rain-driving seasonal trough passed through Anoopgarh, Churu, Agra, the centre of low pressure area, Chandbali and into the east-central Bay. Numerical predictions by international models suggest another monsoon system (a likely depression) spinning out from the extreme northeast Bay sometime next week.

As if on cue, the seasonal trough is tipped to dip back into the Bay and appropriate the system, pull it towards the Orissa-Andhra Pradesh coast and possibly kick-start a rousing wet session over the southeast coast. Here, it would be ideally placed to cause the monsoon current to sweep the southern peninsula (including the rain-deficit southwest coast) to generate good rainfall.

The exact location where the system forms becomes crucial in this context — extreme northeast Bay normally would mean concentrated heavy rains over the east and the northeast as happened during the just-concluded session. But it is also possible that the heavy rainfall that pulverised the seawaters would have brought down the ambient surface temperature levels.

In which case, the system would seek out warmer waters to the immediate west by getting a move in that direction even, while being ensconced within the larger monsoon trough. This should explain the westward movement to the Andhra-Orissa coast, according to forecasters.

The IMD has forecast fairly widespread rainfall with isolated heavy falls over coastal Karnataka and Kerala during the next two days. Extended forecasts for three days from Sunday suggest an increase in rainfall activity along the west coast. A helpful offshore trough from Maharashtra coast to Kerala coast persisted on Thursday.

A warning valid for the next two days said that fairly widespread rainfall is likely over central India also. Rain or thundershowers have been forecast at many places over west Uttar Pradesh, Punjab, Himachal Pradesh and Uttarakhand and at a few places in the northwest, east Rajasthan, south Madhya Maharashtra and Gujarat.

An incoming western disturbance has parked itself over north Pakistan and adjoining Jammu and Kashmir. The interaction with the prevailing monsoon ‘low’ would bear some watching, especially in view of the extended stay that models credits it within the region.

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