US airline JetBlue has cancelled almost 1,300 flights over the coming fortnight as the rapid spread of the Omicron variant wreaks havoc for airlines. Airlines are struggling with the combination of harsh winter weather in some parts of the northern hemisphere and the spread of Omicron, which has caused surging Covid-19 case numbers in countries including the UK, France, Italy and the US. US airlines in particular are struggling with the Omicron surge because many are running schedules at or near pre-pandemic levels. United Airlines on said Wednesday that 150 flights were cancelled because of Covid-19 staffing issues, and on Thursday it cancelled another 188. Delta Air Lines cancelled 87. JetBlue’s cancellations will continue until 13 January. “We expect the number of Covid cases in the north-east [US] where most of our crew members are based to continue to surge for the next week or two,” a JetBlue spokesperson said. “This means there is a high likelihood of additional cancellations until case counts start to come down.” A United spokesperson said: “The nationwide spike in Omicron cases this week has had a direct impact on our flight crews and the people who run our operation.” British airlines, on the other hand, had announced reduced schedules weeks ago because of low demand. British Airways has not been forced to cancel any flights at the last minute because of the spread of the variant, even though some workers are off sick. EasyJet also said it had not suffered from any staffing issues. More than 4,700 flights worldwide that were originally scheduled for Thursday have been cancelled, according to FlightAware, a data company. More than half of those cancellations were confirmed only on the day. It added to almost 2,900 cancellations on Wednesday, the data showed. There were 152,000 flights on 29 December, about 16,000 fewer than in 2019 before the pandemic but better than the same day in 2020, before vaccines were widespread in rich countries, according to FlightRadar24, another data company. Nick Cunningham, an aviation analyst at Agency Partners, said: “We suspect that this will prove to be a relatively short-lived disruption, because the exponential of cases is so steep, suggesting a rapid peaking – but that also implies that while it lasts it could be very disruptive. “Unlike previous waves the impact could be more on the supply side (in the sense of airlines struggling to operate capacity), than from weak demand or government restrictions.”