A relatively warmer December in Central India this winter is attributable to the El Nino effect that has generated stronger jet streams than before.
The jet streams are supporting western disturbances, which, in turn, are causing humidity to seep into the Central part of the country.
The jet streams, which are striking the western parts of country with greater frequency, also prevented wind patterns from turning dead northerly.
Even beginning of January – considered part of the coldest fortnight winter – has remained warmer than expected. Regional Meteorological Centre director Dr D P Dubey explained jet streams as very high velocity winds that blow at the rate of about 200-300 km per hour at the height of 10 km over 25 degree latitude.
These are precipitated by El Nino effect where a warm sea throws up air at the equatorial region, which then descends at 25-30 degree latitude at full blow, Dubey told Hindustan Times.
That is why, he pointed out, temperature in the Central India is not dipping to expected level even as northern parts of the country are reeling under cold waves.
Although the minimum temperature in the State touched normal (between 10-11 degrees) on occasions, most of the days in December remained warmer than expected with minimum temperature recording two to three degrees above normal.
In the first 10 days of the month, the minimum temperature across state remained three to four degrees above normal. The lowest minimum temperature for the month of December was recorded at 9 degrees this season – the third highest during the last ten years.
Before this, in 2002 and 2004 higher lowest minimum temperatures were recorded at 9.9 ad 9.7 degrees respectively. During all other years the temperature plunged lower, even touching the 5.8 degrees mark in 1996.
The Met office said that there are no chances that the temperature would dip considerably in coming days though a slight plunge of mercury might be expected.