A thick layer of hailstorm hit Delhi-NCR left Noida and adjoining areas in the National Capital region white. The minimum temperature on Thursday was at 15 degrees — 6 notches higher than the normal temperature of the season. Twitter/Padmaja JoshiMinimum temperatures are likely to fall by 4-6 degrees Celsius over northwest India from February 8. A fresh western disturbance is likely to affect the whole of northwest India from February 10 onwards, an India Meteorological Department (IMD) bulletin said.Twitter/sudhakarThe rain accompanies by hailstorm was able to bring down the high pollution level in Delhi. The Air Quality Index at 4 pm on Thursday was recorded at 176 or moderate. However, weather analysts say that moderate air quality will not last long.Twitter/Mahesh JoshiUnder the influence of western disturbances, scattered rain and high wind speed have significantly improved the air quality. The southwesterly winds from the Arabian sea will bring more moisture and foggy conditions may occur for the next few days, System of Air Quality and Weather Forecasting and Research (SAFAR) said in its daily forecast. This year’s western disturbances have extended because of the ongoing polar vortex, which has pushed down Arctic winds.Twitter/sudhakar(With IANS inputs)