New Delhi, Dec. 25 -- Hours after strong winds helped improve Delhi's air quality to "poor" levels on Wednesday, the Commission for Air Quality Management (CAQM) lifted restrictions under Stage 4 of the Graded Response Action Plan (Grap), despite forecasts that it was expected to worsen. Grap curbs under stages 1, 2 and 3 curbs remain for now. Delhi's 24-hour average air quality index (AQI) was 271 at 4pm, according to the Central Pollution Control Board (CPCB) national bulletin, significantly better than 412 ("severe") at the same time a day earlier. In the evening on Wednesday, the CAQM issued orders rolling back Grap-4 curbs in view of, what it said was, the "disruptive nature of restrictions", the air quality improvement, and forecasts for the coming days. The decision to roll back Grap-4 curbs comes ahead of what is historically, driven by low temperatures, fog and local sources, the second peak of Delhi's annual winter pollution crisis during the holiday period at the end of the year, typically the last week of December. This appeared to be borne out by forecasts. On Wednesday, the Air Quality Early Warning System (AQEWS) for Delhi said AQI is likely to be back in "very poor" from Thursday to Saturday. "The outlook for the subsequent six days is that the air quality is likely to be 'very poor,'" it added. Grap-4 curbs were implemented on December 13 , when AQI in the Capital deteriorated to "severe". The city has experienced four "severe" air days this month - December 23, 15, 14 and 13 - and seven overall this year. On Wednesday, after a 14-day streak of "very poor" and "severe" air days, AQI improved by more than 100 points over the course of the day, registering at 325 (very poor) at 12 pm, 231 by 8 pm and 222 at 10 pm. At least eight out of the 39 active ambient air quality stations were recording "moderate" air at the same time at 10 pm. The CPCB classifies an AQI of 51 to 100 as "satisfactory", 101 to 200 as "moderate", 201 to 300 as "poor", 301 to 400 as "very poor", and a reading above 400 as "severe"....