National Weather Forecast: Tuesday, January 14

Air quality suffered a knock in Chennai on Tuesday with heavy smog engulfing parts of the city as people discarded old items and lit bonfires to observe Bhogi, the first day of Pongal. Visibility was poor in a number of places this morning as thick smoke billowed, the first time air quality has deteriorated since early November, when a steady stream of northerly to north-easterly winds, allegedly from stubble burning across the plains up North, brought in pollutants.

The PM2.5 level reading stood at 223 at 11 am in Manali (monitoring station of the Central Pollution Control Board. It logged in at 175 (moderate) at Manali Village (monitored by Tamil Nadu Pollution Control Board); 145 (moderate) at the Alandur Bus Depot (Tamil Nadu Pollution Control Board) and 132 (moderate) at Velachery (both Central Pollution Control Board).

Bhogi is a day when people discard old belongings and focus on new ones. They assemble at dawn in the states of Tamil Nadu and Andhra Pradesh to make a bonfire of the discarded items. The house is cleaned, painted and decorated to give a festive look.

Despite all this burning, however, air quality in Chennai was superior to many parts of Delhi. At 1 pm today, these were the readings for key areas in the National Capital:

Anand Vihar: 322 (very poor); Ashok Vihar: 340 (very poor); Bawana: 311 (very poor); Mathura Road: 282 (poor); IGI Airport: 202 (poor); and Jawaharalal Nehru Stadium: 300 (very poor).

Request from Chennai Airport

As a precautionary measure, the Chennai Airport requested the public in the vicinity of the airport not to burn waste materials that could create thick smog for fear that it would lead to flight diversions as happened in 2018. The burning of waste brings down visibility, leading to diversions/cancellation of flights and passenger inconvenience. The airport authorities had distributed pamphlets sharing their concerns in villages in and around the airport and thanked the public in advance for their compliance.

Bhogi is also observed in neighbouring Andhra Pradesh where, in the villages, the horns of oxen and buffaloes are painted in colours. In most rural parts of the state, farmers have their harvest ready or would have even realised money from the harvests. Air quality ranged from being moderate to poor in Andhra Pradesh and Telangana on Tuesday morning, with Visakhapatnam (PM2.5 of 278) and Rajamahendravaram (208) returning very poor levels. It was moderate in Amaravati (164) and Tirupati (146). In Telangana, the overall air quality level was moderate with three monitoring centres in Hyderabad reporting moderate numbers while data was not available from the two other centres in the city.

A clear sky over Bengaluru’s UB City on Tuesday. Pic: GRN Somasekhar

Westerly in awe of successor, weakens

As for weather for the rest of the country, an incoming active western disturbance stalled over Afghanistan and adjoining Pakistan by Tuesday morning, apparently in view of the fact it is expected to be tailed by another strong system from as early as tomorrow Wednesday. No two strong weather systems can exist in the same latitude and affect a geography, other than in exceptional circumstances.

The India Meteorological Department (IMD) said this morning that the parent western disturbance had thus weakened even before crossing into Indian territory. The offspring circulation that it had managed to send across to North-West Rajasthan, too, has weakened in the process. Their combined impact will be witnessed at best during the next 24 hours over the hills of North-West India,

Weather peaks for hills, plains in North-West

But the successor disturbance will have enough steam to work up the weather over these parts, with the peak intensity of precipitation likely to take place tomorrow, the IMD said. Widespread to fairly widespread rain/thunderstorms accompanied by hail/lighting, has been forecast for the hills.

Over the plains, scattered to fairly widespread rain/thunderstorms accompanied by hail/lighting is likely over Punjab, Haryana, Chandigarh, Delhi and West Uttar Pradesh during the same period. The rest of the plains will witness scattered to fairly widespread precipitation between January 18 and 20 (Saturday and Monday) with peak activity on January 19 (Sunday).

Yesterday (Monday), the highest day temperature of 36.8 degrees Celsius was recorded at Karwar in Karnataka, and the lowest night temperature was reported to be 5.4 degrees Celsius in Datia, West Madhya Pradesh.