LUCKNOW, Nov. 15 -- Dense fog enveloped several parts of Uttar Pradesh on Saturday morning, causing a sharp drop in visibility. Bareilly (IAF) recorded zero visibility, while it fell to 80 m at the Meerut observatory and 100 metres in Moradabad. Visibility was recorded at 400 m at Hindon (IAF), 600 m at Noida airport, 700 m in Aligarh and 900 m at Agra (IAF). Visibility dropped to 50 metres in Kushinagar, 200 metres in Azamgarh, 350 metres at Lucknow airport and 400 m in Gorakhpur. It was recorded at 500 m in Ayodhya, 600 m in Shrawasti, 700 m in Ballia and 800 m at Varanasi airport. "There is a possibility of scattered rainfall in western UP on November 15 under the influence of a Western Disturbance. This may be followed by increased fog and a significant drop in temperatures across the region in the second half of November," said Atul Kumar Singh, senior scientist at the Regional Meteorological Centre, Lucknow. The current western disturbance is likely to bring scattered rainfall to some districts of western Uttar Pradesh over the next 24 hours. Thereafter, the influence of north-westerly winds is expected to increase, leading to denser fog and a significant drop in temperatures across the region during the second half of November. This is likely to bring down day and night temperatures by 3-5degC between November 16 and 18, bringing them closer to normal levels. The drop in temperatures will intensify the cold and lead to an immediate increase in fog....