More than 3,700 flights within, into or out of the US had been cancelled by 9.30am ET on Saturday 14 November, according to FlightAware figures reported by NBC News. That is up from more than 3,400 at 6.45am ET.
NBC News said 1,990 delays had been logged by the same time. CBS News and Patch, also citing FlightAware, put Saturday cancellations at more than 3,800, but neither gave a time for the count. Patch said the totals were expected to rise.
Delay counts vary widely. CBS News gave around 2,000, while Patch cited another count showing nearly 11,200. The reports do not explain the gap.
Atlanta, Chicago O'Hare and New York JFK are named among the worst-hit airports.
Friday's figures also conflict. NBC News puts Friday cancellations at more than 7,000. ABC News reported 9,132 at 6.52am EST from FlightAware, and a FlightAware figure of 8,860 was reported earlier on this blog. None of the reports explains the difference.
NBC News says airlines had to reposition planes and crews, and some crews may have hit duty-time limits. The FlightAware figures have not been independently checked.