Monsoon withdrawal delayed in the last leg

A sudden turnaround in the south-west monsoon, only to be expected given its truant nature, has resulted in moderate to heavy rains in the last leg of the four-month season. This has effectively brought to a halt its early withdrawal from north-west India. The withdrawal is not expected to be reversed until rains diminish in the southern peninsula. Indications are this could take the rest of the month.

So, this year too, the south-west monsoon is likely to spill over to October after a delay in its withdrawal, beyond the normal date of September 30. This is a trend that has persisted for the last few years. This makes it likely that the arrival of the north-east monsoon could get delayed over the southern peninsula. 

Meanwhile, the ongoing spell in the south peninsula has reduced the peak rainfall deficit for the country as a whole from 16 per cent to 15 per cent as on September 18. With another 12 days to go and rains forecast to continue, it is likely that the season might end with a deficit of 14 per cent or thereabouts. It may be higher by 2 percentage points than the India Meteorological Department may have factored in its earliest long-range forecasts but goes to crown the national forecaster in glory. IMD had forecast a deficit monsoon for this year to start with and stayed with it for the rest of the season, refusing to be fooled by the ‘flash-in-the-pan’ surpluses during its humongous run in early June and July. 

September began with the worst start possible, running into deficits of a massive 55 per cent during the first full week ending September 9 when the monsoon ran dry in the entire north India even as the south began to slip under a renewed rain spell. The sustained spell in the south helped the monsoon to improve the deficit significantly to 30 per cent during the week ending September 16. The excess spread out to more parts of the northern peninsula although at the expense of Kerala, Tamil Nadu and south interior Karnataka. This is how the deficit for the country as a whole has come to 15 per cent latest (as on September 18).   

During September, the cumulative rainfall for the country as a whole had slipped to 42 per cent below average before recovering a bit in east and central India. The rains have been very weak in Uttar Pradesh, Madhya Pradesh, Bihar and West Bengal during the month. The dry spell in Madhya Pradesh, however, is good for the maturing soyabean pods, according to experts. But the maturing groundnut and cotton crops in Gujarat have run out of the much-needed wet spell since late July. Similarly, the guar crop in Rajasthan has come under moisture stress and requires at least one or two spells.

Here, it is likely that some rain will come to its aid next week as a prevailing depression stays put.

According to the extended range weather forecast by the India Met Department, India Institute of Tropical Meteorology and the Hyderabad centre of the India Council of Agricultural Research, rainfall is likely to improve over southern peninsula and parts of central India during the next 10 days.

Moderate to heavy rainfall is expected over certain parts of Maharashtra, the west coast, and the east coast till the end of this month.