Concerns with IMD’s Prediction

Why in news?

India Meteorological Department (IMD) has predicted a normal and well-distributed rainfall in the second half of the monsoon season.

What is the status of 2018 monsoon?

• Over 80 per cent of the country’s total geographical area has already received normal or above normal rainfall.
• Part of the rain-deficient region of Bihar, Jharkhand and the northeast, too, has received some welcome showers in the past few days.
• Though the pace of kharif sowing has so far been slower than in the last year, the estimated 7.5 per cent lag in crop planting can be made up in the next few weeks since the sowing season is still not over.
• Besides, the total water stock in the country’s 90-odd major reservoirs has already swelled to about 11 per cent above normal for this time of the year.

What is the significance of IMD’s prediction?

• In the last 17 years since 2001, the weather office’s preliminary predictions have been on the mark on only a couple of occasions though, admittedly, the margin of error has gradually been narrowing, especially since 2010.
• This is despite perceptible advances in the IMD’s short- and medium-range weather gauging capabilities, expansion of data-gathering infrastructure and availability of better-computing facilities.
• Recently IMD has predicted that second half of the monsoon August-September will have normal and well-distributed rainfall.
• The markets have, predictably, reacted positively to the optimistic monsoon outlook.

What are the issues with IMD’s prediction?

• The IMD’s prediction rainfall seems to have largely quelled the disquiet caused by other weather watchers by projecting sub-par monsoon rainfall this year.
• The past accuracy record of the IMD’s long-range monsoon forecasts, issued normally in April every year, does not inspire much confidence.

• The major reason for the wide disparity in the monsoon outlook of the IMD’s is their perception of the likely adverse impact on the rainfall of some key monsoon-influencing parameters that are threatening to turn unhelpful.
• The local private weather forecaster, Skymet anticipates below-average rains this year on the assumption that oceanic parameters are at present unfavourable for the monsoon’s progress.
• The IMD, on the other hand, has stuck to its original stand that the rainfall would be normal or close to that throughout the season.
• The sharpest contrast in the forecasts by Skymet and the IMD is in the rainfall projections for the current month of August.

What is the way forward?

• However, regardless of whether the IMD or Skymet proves correct, the chances of any major ill-effect of the monsoon on agriculture or the economy seem quite dim at this stage.
• It should help sustain water supply for crop irrigation and hydel power generation in the post-monsoon dry season as well.
• Though all these are reassuring factors, the proverbial uncertainties of weather cannot be brushed aside.
• Thus the ultimate outcome would depend on how the weather pans out between now and the harvesting of crops from October onwards.

Source: Business Standard