The winters this time remained fog- free, which is a very uncommon phenomena to be witnessed during winters. Generally, fog starts developing from mid- November and continues up till Mid of February. Sometimes, there is a prolonged spell of dense fog, which usually lasts from days together and covers the entire Indo-Gangetic plains right from Punjab to East Uttar Pradesh and Bihar.
However, this year due to lack of winter rains and lower humidity levels, dense fog was seen in isolated pockets and that too for a very short duration. Also, fog is not expected to make a return anytime soon.
Contrary to the anticipation of fog over the Northwest Plains, weather remained clear over almost entire Northwest India on the morning of January 14. In the last two days, scattered rains were seen over Punjab, parts of Haryana, West Rajasthan and isolated pockets of West Uttar Pradesh. Whenever a Western Disturbance moves away after giving rains over the Northern Plains, dense to very dense fog is generally seen over Northwest India. Fog formation can be attributed to rise in humidity levels due to rains, drop in minimums, clear sky and light winds.
Whereas, this time weather remained clear and fog did not show up. The only reason behind this is the continuous flow of winds. Although, the winds changed their direction from easterly/ southeasterly to westerly/ northwesterly. However, during this transition, speed of winds remained in moderate category which did not allow the condensation to take place near the earth surface. Today, the visibility recorded at Palam airport (Delhi) was 800 metres which is just fine with clear sky. Thus, Delhi and NCR including most parts of Northern Plains seems to escape the fury of fog.
Image Credit: Scroll
Please Note: Any information picked from here must be attributed to skymetweather.com
