A dense fog enveloped giant swathes of the Capital on Wednesday morning, with visibility dipping to under 100 metres at a number of observatories, even because the temperatures remained above regular for a 3rd consecutive day. The India Meteorological Division (IMD), in the meantime, issued a yellow alert for 4 days, until Sunday, warning of dense fog and thunderstorms attributable to a recent western disturbance.
Heavy fog at Janpath on Wednesday morning. (Arvind Yadav/HT Picture)
On the day, Delhi recorded a minimal temperature of 8.4 levels Celsius (°C). Though it was down from a minimal of 9.9°C recorded a day earlier than, it nonetheless was one diploma above the traditional for this time of the 12 months. The utmost temperature was 22.4°C, two levels above regular and up from a most of 20.8°C recorded a day earlier than.
IMD forecast the minimal to rise as much as 11°C by Friday, earlier than dipping once more from the subsequent week. It forecast a most temperature of 21°C.
An IMD official stated, “A moderate fog is likely to form in the morning for the next three days. A dense fog has been forecast for Sunday.”
On Wednesday, a “dense fog” was recorded on the Safdarjung and Palam observatories, with visibility falling to 100 metres between 5.30am and seven.30am.
IMD classifies it a “shallow fog” when the visibility is between 500 metres and 1,000m, a “moderate fog” when visibility is between 200m and 500m, a “dense fog” when visibility is between 50m and 100m, and a “very dense” fog if the visibility falls under the 50-metre threshold.
Elaborating on the explanation for issuing a yellow alert from Thursday to Sunday, the IMD official cited above stated: “Due to a fresh and more active western disturbance, predicted to start influencing the Capital from Thursday, we might see some very light to light rain towards the evening on Thursday. Weather conditions might get more intense on Friday, when Delhi is likely to experience moderate rain and thunderstorms, accompanied by lightning and gusty winds of speed 30-40 kmph.”
On Wednesday, solely two climate stations recorded hint to mild rainfall. In response to IMD knowledge, Pitampura and SPS Mayur Vihar stations every clocked 0.5mm of rainfall between 5.30am and eight.30am. There was no rainfall at some other station later within the day.
Air high quality improves
The sunshine drizzle late on Tuesday night and a rise in wind velocity assist enhance Delhi’s air high quality.
Delhi recorded a 24-hour common air high quality index of 336 (“very poor”) on the day, which was higher than the earlier 24-hour common of 369 (“very poor”)—when the fourth stage of the graded response motion plan (Grap 4) was revoked by the Fee for Air High quality Administration (CAQM)—based on the Central Air pollution Management Board’s (CPCB’s) every day bulletin.
The Air High quality Early Warning System (AQEWS) for Delhi, in the meantime, forecast the air high quality to remain within the “very poor” class on Thursday, however predicted an enchancment thereafter.
The air high quality this month has been a narrative of two halves. Till December 15, the AQI was comparatively cleaner than different years, recording “moderate” or “poor” AQI aside from December 8, when it recorded an AQI of 302 (“very poor”).
Then, a four-day streak of “severe” air was recorded from December 17 to December 20, forcing the imposition of Grap Stage 4, below which colleges declared hybrid lessons for all lessons, non-emergency business automobiles have been banned and work timings have been staggered to cut back vehicular air pollution on roads. The six “severe” air days in a seven-day interval between December 17 and 23 was the very best since 2021, when six consecutive “severe” help days have been recorded.
CPCB classifies AQI between 0 and 50 as “good”, between 51 and 100 as “satisfactory”, between 101 and 200 as “moderate”, between 201 and 300 as “poor”, between 301 and 400 as “very poor”, and over 400 as “severe”.
“The air quality is likely to be in ‘very poor’ category on Thursday. The air quality is likely to be in ‘poor’ category on Friday and ‘moderate’ category on Saturday. The outlook for subsequent six days is that the air quality is likely to be in ‘moderate’ to ‘poor’ category,” the AQEWS bulletin stated on Wednesday night.