Winter may bid adieu to the nation this year without unleashing the biting cold that normally leaves people shivering. As a result of the continuing effects of El Nino, only a moderately cold weather is expected to continue through January.
In fact, on Friday Delhiites witnessed a nip in the air and fog that led to cancellation of 64 trains, after over a fortnight of unusually warm weather.
The minimum temperature dipped to 9.6 degrees Celsius and the maximum hovered at 15.6 degrees Celsius, a drop of four degrees, bringing some relief from the unusually warm winter.
Nominal fluctuations in temperature, along with fog and overcast sky, will be experienced due to the impact of Western Disturbance which is expected to last till January 17-18. Minimum temperatures are expected to dip just a few degrees in the hilly States in coming days. North-western plains may also witness temporary drop in both day and night temperatures. But that is it. There are no fears of the spine-chilling cold usually experienced in January.
The mercury is expected to start rising by the third week of January in most parts of the country. The India Meteorological Department (IMD) has said that there is little hope of a drastic drop in temperatures in between. The El Nino effect is expected to continue till the end of February.
The sources in IMD pointed out that winter temperatures in El Nino years are usually above normal. This was seen in 2010, 2009 and 2003, which were also El Nino years. Hence, following the trend of December, the temperature in January would also be expected to be above normal. Further, duration of the day will also increase gradually. This
will lead to rise in radiation from the Sun, thereby also raising the temperature, weather experts said.
They listed global as well as regional reasons for this warm winter. Globally, it is the persisting El Nino phenomenon, which is one of the strongest and most prolonged. It refers to a condition of warming of the Pacific Ocean which in turn spreads to the Indian Ocean with a lag of about two to three months, leading to a warming effect over the sub-continent.
Amongst the regional causes is absence of strong Western Disturbance (WD), which is the extra-tropical storm that develops over the Mediterranean Sea and brings moisture-laden winds to north-west India. “This leads to snowfall in the Himalayas and rainfall in Delhi. Rain plays a key role in intensifying winters,” they added.
Though frequency of Western Disturbances has been normal, but their intensity was on the lower side. Moreover, the path of these weather systems has also been confined to the higher reaches of Western Himalayas. However, none of these systems have been able to give a heavy spell of rain and snow over the northern hills, they said.
However, post El Nino conditions may augur well for the country, leading to la Nina cycle. The reverse of El Nino is associated with the cooling of surface temperature of the Pacific Ocean.
The weather scientists explained that from 1972 to 2010, an assessment of El Nino conditions indicates that la Nina conditions have been witnessed in the years after El Nino. These result in plenty of rainfall.
The meteorologists added that la Nina conditions might start in May-June. They expressed optimism that monsoon should be above normal this year. According to them, probabilities of deficit monsoon in 2016 are thus very low.