The dense fog that blanketed most of the country over the weekend has begun to return, sparking additional delays and cancellations during one of the busiest travel times of the year. Residents of Dubai took to Twitter to share their experiences of their fog-ridden city, with some remembering particularly bad conditions almost a decade ago. The National Centre for Meteorology (NCM) issued an advisory Saturday afternoon warning that it expected thick fog to develop over the coast, as well as rural and northern parts of the country overnight and into Sunday and Monday mornings. “There is a good chance of fog formation over the internal and coastal areas, especially over northern areas during the next two nights and early mornings,” an NCM meteorologist said. “The horizontal visibility will decrease to less than 100 metres over some areas during the fog formation.” The fog will be heaviest after midnight and before 10am, he said. “It is normal to have fog this time of year because there is more water vapour in the air, variable light winds and also clear skies – these are all conditions that tend to form fog,” he said. Some areas of Dubai were under more fog than others, with the Marina only suffering from patchy fog. Abu Dhabi International Airport, Liwa, Madinat Zayed, Sweihan and the area around Al Maktoum International Airport experienced visibility of less than 50 metres on Saturday and could be faced with the same conditions on Sunday and Monday, he said. The reduced visibility forced a number of flights to or from Abu Dhabi International Airport to be delayed or cancelled. "Abu Dhabi International Airport is witnessing heavy fog this weekend, which is anticipated to continue to the early morning of Sunday 24 December. Therefore, departing and arriving fight schedules may be affected," an airport spokeswoman said in a statement to <em>The National</em>. “Abu Dhabi Airports would like to advise passengers to contact their respective airlines for an update on their flight’s schedule or contact the airline customer service agents at the airport.” An Etihad Airways spokesperson said “several” of its flights were delayed or cancelled over the weekend. Affected guests were provided refreshments at the airport or hotel accommodation. “As a consequence of the disruption, some return flights have also been cancelled or delayed,” the Etihad Airways spokesperson said. “Etihad Airways’ Guest Services team is actively working to rebook affected guests with onward connections. The airline continues to monitor the weather conditions in Abu Dhabi and has contingency plans in place should there be any further disruption to flight schedules.” Travellers booked on flights to or from Abu Dhabi over the next few days are being advised to check the status of their flights before proceeding to the airport. “Etihad Airways regrets any inconvenience caused, which is beyond our control, and thanks guests for their understanding during this holiday period,” the spokesperson said. “The safety of our guests and crew remains our utmost priority.” Historical data on the flight-tracking application Flightradar24 showed that most flights departing from Abu Dhabi since Friday night and early Saturday morning were delayed by at least two hours. Some, like Etihad Airways flight EY250 to Kozhikode, were as much as six hours late to depart. EY250 was supposed to depart at 10.15pm, but didn’t get off the ground until 4.20am, according to FlightRadar24. The Etihad Airways flight EY315 to Riyadh was delayed by five hours when it finally took off this morning at 7.02am. A number of travellers vented their frustrations on social media about their delayed or cancelled flights and missed connections. “Stuck in Abu Dhabi airport,” tweeted Sarah Watts. “Staff have no idea what to do with people who are going to Brisbane. Flight was cancelled hours ago. What’s going on @EtihadAirways ???” Many of the complaints were greeted with a sympathetic reply from the official Etihad Airways account on Twitter. “We have many guests who have been affected this morning, we understand it's frustrating. Please be assured that we are working as hard as we can to get as many guests out of Abu Dhabi as we possible. We kindly ask for your patience at this time. Thanks *Joe.” _________________ Read more: _________________ In Dubai, three flights were diverted from Dubai World Central (DWC) to the Dubai International Airport (DXB) because of the fog. A spokeswoman for Emirates said none of the airline’s flights were delayed or cancelled due to the fog and that it was “business as usual” on Saturday. No major traffic accidents were reported by Dubai or Abu Dhabi police.