Abnormal monsoon leaves IMD confused, wreaks havoc across India
New Delhi, Oct 04: Most parts of the country received above average rainfall this monsoon which is yet to begin its retreat. Kerala and Karnataka suffered heavy losses due to incessant rains and floods, while many parts of Bihar, including the capital Patna, is still inundated.
The most bewildering part is that during the onset of monsoon, the concern usually is whether it would rain as much as it should. Then during the middle of the monsoon, IMD releases an asessment forecasting to what extent the rainfall will meet the projection. IMD's August 1 monsoon assessment says that the rainfall would be 100 per cent of what is normal with a variation of 8 per cent. But, it rained so much in August and September that that actual rainfall was 22 percentage points stronger than projected.
Moreover, the monsoon has still not retreated which is highly abnormal as previous latest retreat was recorded in 1961 when the monsoon retreat began on October 1.
The IMD said on August 1 that the monsoonal rain would be 100 per cent of what is normal with a variation of 8 per cent. On the higher side, monsoon has proved to be 22 percentage points stronger.
As incessant monsoon rains has wreaked havoc across North India, especially Bihar and Uttar Pradesh, with more than 150 reported deaths. Of these, 104 deaths have been reported from Uttar Pradesh alone, while the toll in Bihar has climbed to 40.
Scientists attribute it to the rising temperatures, creating a more moisture-laden monsoon system and higher levels of precipitation. Studies have found that a threefold increase in widespread extreme rainfall over central India since 1950, as a result of warming in the northern Arabian Sea.
Another study, found that rainstorms in North India have become 50% more common and 80% longer. One important reason for this is that an atmosphere that is warmer can hold more water vapour. The world has so far heated about 1°C since pre-industrial times and, around the world, heavy rainfall has increased.
Monsoon made a delayed entry over Kerala on June 8, a week after its normal date of arrival. The deficiency in June was 33 per cent but it picked in later months.