Unforeseen El Nino marred rain forecast

MONSOON WATCH

What went wrong with the monsoon and the weather office's long-range monsoon prediction this year? The India Meteorological Department (IMD) is blaming the emergence of a weak El Nino (warming up of the equatorial central Pacific ocean) that could not be foreseen.

And, it adds that it is not the only meteorological organisation to err on this count. Most others, too, could not foretell a poor monsoon. All local and international climate prediction centres had anticipated a neutral El Nino and a near normal monsoon rainfall.

The IMD's preliminary analysis of the monsoon failure has linked the break in the agriculturally-crucial month of July to unusual warming of the equatorial central Pacific towards the end of June and the simultaneous below normal sea surface temperature of the equatorial east Pacific.

Though the monsoon revived in August, bringing almost normal rainfall in most parts of the country, it became subdued again in September.

"Analysis of past rainfall data shows that September rainfall is invariably below normal in the years of warming up of the central Pacific during the monsoon," the IMD said in its end-of-season report on the monsoon.

The ocean warming caused anomalous air circulation features, enhancing typhoon activity over the north-west Pacific. Most of these systems moved towards the north and north-east, impeding the revival of the monsoon. Similar anomalous features were observed in the 2002 monsoon season, causing wide-spread drought.

According to the IMD, the drought was confined this year to 18 per cent of the total area which received between 25 and 50 per cent of its normal seasonal rainfall. Of the 524 meteorological districts, 132 districts (25 per cent) experienced moderate drought and 36 districts (7 per cent) severe drought.

The major affected areas include Himachal Pradesh, west Uttar Pradesh, Punjab, west Rajasthan, Vidarbha and Telangana.

However, from the agricultural viewpoint, the affected area was much larger. Regions like east Rajasthan, Haryana, Jharkhand, Marathwada and Tamil Nadu also suffered from low and ill-distributed monsoon rainfall. The crops planted relatively early after the good pre-monsoon rainfall in June had withered in July due to lack of rains in several areas. Similarly, crops sown late in many areas after good August rains faced moisture paucity due to a deficient monsoon in September.

The post-monsoon showers (after September 30) have, by and large, been beneficial for crops. But, the current wet spell due to western disturbances in the hitherto rain-starved north-western rabi belt is being viewed as a mixed blessing.

While it will benefit crops that are in the grain-formation and development stages, mature crops, needing reaping, may been damaged to an extent.

It may also lead to greater crop damage from attacks by caterpillars, notably in Madhya Pradesh where crops over about 1 lakh hectares in nine districts are said to have been devastated by this pest.

Cotton picking was already in an advanced stage and the harvesting of early planted paddy crop had just begun when the present rainy spell commenced. These operations are likely to be hampered.

As will be the harvesting of early sown and shorter duration crops of groundnut, maize, bajra and some others.

However, these rains are good for early rabi sowing. In fact, reports indicate that the sowing of rabi vegetables and oilseeds like toria and sarson (mustard) has already begun, especially in the areas which remained unsown in the kharif season.

The drop in temperature as a result of the rains is likely to facilitate good germination.

The low temperature is also good for the late planted basmati in Haryana. It will improve the milling quality, resulting in lower losses due to breaking of grains.