North India can expect more warm days this week. According to the India Meteorological Department (IMD), the maximum temperatures are likely to remain 5 to 7 degree Celsius above normal over many parts of northwest India for the next three days.
This may adversely impact the wheat crop that is approaching the stage of reproductive growth, which is sensitive to temperature, the meteorological department warned through a late evening press release issued on Monday.
"High temperature during flowering and maturing period leads to loss in yield. There could be a similar impact on other standing crops and horticulture," met said.
Last year, in March – the warmest recorded in India since 1901 – wheat yield had shrunk by 2.5 per cent because of the heat.
In its advisory, the met has urged farmers to regularly check if crops appear to be under stress, in which case light irrigation can be provided.
To mitigate the impact of higher temperatures, add mulch in the space between the two rows of vegetable crops to conserve moisture in the soil and maintain its temperature, met said.
Mahesh Palawat, vice-president of meteorology and climate change at private weather forecasting agency Skymet, said the rise in temperatures in February was unusual.
He said the maximum temperatures in most places in Himachal Pradesh, western Rajasthan, parts of western Himalayas, parts of east Rajasthan, Saurashtra and Kutch, Konkan, Goa and in a couple of places in Uttarakhand and Gujarat had been significantly above normal for the last few days but were dipping now.
“The two weather factors that we (Skymet) can identify for this unusual rise in temperatures is that though successive western disturbances are approaching the western Himalayas, they are not causing any significant rain or snow,” Palawat told Business Standard. “Secondly, the gap between these western disturbances is very less. Therefore, the cold winds from the north are not setting in, which would have arrested the rise in temperatures.”
There is also the anticyclone over the northeastern part of the Arabian Sea, which has now moved over southwest Rajasthan.
“Due to this anticyclone, hot and dry winds from Balochistan, South Sindh and Thar Desert are reaching northwest India as well as Gujarat, Maharashtra, and Karnataka,” Palawat explained. “The absence of any significant weather activity, bright sunshine, and dry and hot winds are responsible for this unusual spike in temperatures.”
He said that Skymet did not foresee any relief for northwest and central India and parts of the west coast in the coming week, and added that warmer than usual temperatures will adversely impact the quality and yield of crops.
The IMD, meanwhile, said that maximum temperatures had been in the range of 35 to 39 degree Celsius over many parts of Gujarat, Rajasthan, Konkan, Goa and coastal Karnataka during the past week (February 13-20), and were currently above normal by 4-9 degrees.
The temperatures are above normal by 6-9 degrees over some areas of Saurashtra, Kutch and southwest Rajasthan. The maximum temperatures were in the range of 23-28 degree Celsius over parts of Himachal Pradesh and Uttarakhand during February 15 to 20; and 5-11 degrees above over Punjab, Haryana, Chandigarh and Delhi, where they touched 28-33 degrees during February 18-20.
Met said that significantly higher than normal maximum temperatures over northwest India, Gujarat, Konkan and Goa may be attributed to: One, the absence of any active western disturbance in February, and the dry spell prevailing over the plains and subdued rainfall or snowfall over hills; and two, the anticyclone over south Gujarat.
Over the Konkan belt, weaker sea breeze and stronger land breeze, plus the anticyclone, have caused the sudden surge in heat, met said.
The meteorological department has, meanwhile, withdrawn the heatwave warning it had issued for isolated places in Kutch and Konkan with the sea breeze leading to a drop in temperatures.
A heat wave is declared if the maximum temperature of a station reaches at least 40 degrees Celsius in the plains, at least 37 degrees in coastal areas and at least 30 degrees in hilly regions, and the departure from normal is at least 4.5 degree Celsius.