Winter this year could be slightly colder than last year — a record, unusually-warm spell — but would still be warmer than what is usual, the India Meteorological Department (IMD) has suggested in its first ever winter forecast.
Seasonal temperatures across India, from December to February, would be higher than normal with fewer cold waves over north and north-west India than what is typical. In general, minimum and maximum temperatures over most of India would be 0.5-1.0 C higher than average winter temperatures during 1961-1990, with Jammu and Kashmir and Rajasthan expected to show the widest, upward deviations. Normal refers to average, seasonal temperature over a region between 1961-1990.
Cold wave
Last year was the warmest winter recorded in India since 1901, with the mean temperature nearly 1.25 C more than normal. “This year would likely be warm too but not as much as last year,” said D.S. Pai, Chief Forecaster, IMD Pune.
“This is in line with the overall global warming trends. There may be about the same, or slightly more, cold waves than last year.” IMD officials said there would be updates of likely cold waves, every five days, through the season.
In a research report last year, Mr. Pai and his colleagues said the number and duration of cold waves over India have generally been decreasing over 4 decades. Severe cold waves annually kill about 780 every year. Several deaths were reported in North India during the 2015-16 winter season, in spite of it being extremely warm. The mean temperature between March and May 2016 was also significantly warmer than normal with an anomaly of +1.250C, which was the second warmest ever spring season since 1901.
A raging El Nino, usually responsible for droughts over India, was believed to cause higher than normal sea surface temperatures and warm winters. So far, the annual mean land surface air temperature averaged over the country during 2016 till October was +0.90C above the 1961-1990 average.
The winter forecast has been made with a Dynamical Extended Range Forecasting System developed by the Indian Institute of Tropical Meteorology, Pune, and uses the same physics and climate models used to track the monsoon.
