Delhi-NCR air in severe category, temperatures to dip in northwest India

Air quality remains in 'severe' category in many parts of Delhi NCR on Saturday. Delhi's air quality index this morning is 441, Faridabad, Ghaziabad, Greater Noida and Noida also recorded 'severe' air quality which negatively impacts even the healthy.

This is mainly due to low wind speed not allowing dispersal of pollutants in the air. Due to dry north/north westerly winds, minimum temperatures are likely to fall by 2-4 degree Celsius over most parts of northwest India during the next two days, according to the India Meteorological Department.

Dense to very dense fog at isolated pockets are very likely over Punjab, Haryana, Chandigarh, Delhi, Uttar Pradesh, north Rajasthan, sub-Himalayan West Bengal, Sikkim and Bihar during the next 3 days.

Cold wave or 'severe’ cold wave conditions are also very likely over Punjab, Haryana, Chandigarh, Delhi, Uttar Pradesh, Rajasthan and east Madhya Pradesh during the next two days. Cold day conditions at isolated pockets are also very likely over Punjab, Haryana, Chandigarh, Delhi, Uttar Pradesh and Bihar during the next two-three days, as per the weather department.

According to IMD, a cold day or a severe cold day is classified as such based on two parameters—a minimum temperature of under 10 degrees C and maximum temperature of 4.5 degree C or 6.4 degree C below normal, respectively.

A cold wave occurs in the plains when the minimum temperature is 10 degrees Celsius or below and/or is 4.5 notches lower than the season’s normal for two consecutive days. A cold wave is also declared when the minimum temperature is less than 4 degree C in the plains.

A cyclonic circulation is lying over southwest Bay of Bengal off Tamil Nadu coast in mid tropospheric levels and a trough runs over central parts of south Arabian Sea and adjoining equatorial Indian Ocean to the Comorin area.

The condition is likely to result in scattered to fairly widespread rainfall with moderate thunderstorm and lightning over Tamil Nadu, Puducherry, Karaikal, Kerala, Mahe and Lakshadweep area during the next two days and a reduction in rainfall activities thereafter, as per IMD bulletin.

Conditions are becoming favourable for the cessation of northeast monsoon rains over Tamil Nadu, Puducherry, Karaikal, Kerala and Mahe and adjoining areas of coastal Andhra Pradesh and Yanam, Rayalaseema and interiors of south Karnataka around January 19, IMD's Friday bulletin said.