The year that just went by left Delhi with its foggiest December in fifteen years. According to earlier reports, around 90 hours of fog was predicted for the winter season in 2014. However, Skymet Division had observed that winter in 2014 will experience fog hours ranging between 120 to 130. The month of December 2014 observed 76 hours of CAT III dense fog with 51 hours of zero-visibility fog. In the process, December 2014 became the foggiest December in last 15 years.
The year 2003 observed 73 hours of CAT III dense fog which was the highest before December 2014 observed 76 hours of CAT III dense fog. This is against an average CAT III dense fog of 40.36 hours. As compared to the average of zero-visibility fog, which is 24.45 hours, December 2014 observed 51 hours of zero visibility dense fog. Let's take a look at some interesting stats regarding fog in the month of December over the years:
*2009 had lowest incidents of zero visibility and less than 200 meter visibility
*Extreme Fog: The year 1998 experienced 179 hours of dense CAT III fog and the year 1997 recorded 85 hours of dense CAT III fog hours.
Interestingly though, despite record fog hours, only 46 flights were diverted at the IGI airport. These diversions are lesser in number when compared to flight diversions during previous years. Recently installed forecast equipment and the valuable inputs provided by ISRO's INSAT-3D satellite allowed airport authorities to trace the movement of fog towards the airport beforehand. This allowed them to make adjustments and act accordingly thereby minimizing the overall number of flight diversions for the year.
