It was slow going again on Thursday into Friday for a Delta Airlines flight from New York to Los Angeles.

Delta Flight 975, which had been slated to take off Thursday at 3:30 p.m., was delayed by more than 19 1/2 hours and didn't leave John F. Kennedy International Airport until 11:07 a.m. Friday.

Delta 975 on Wednesday suffered a similar, extended lag.

That flight, scheduled for 3:30 p.m. Wednesday, didn't get off the ground until 10:01 a.m. on Thursday.

A Delta representative said Friday that a combination of staffing shortages and weather caused this latest massive delay: "Delta apologizes to customers on flight 975 operating from New York-JFK to Los Angeles, which was delayed Thursday night due to crew availability and weather affecting the Northeast airspace."

The airline said in an earlier statement about the flight's delay from Wednesday into Thursday: "Delta apologizes to customers on flight 975 operating from New York-JFK to Los Angeles, which was delayed last night due to weather affecting the Northeast airspace. Customers were offered water and snacks, pillows and blankets in the terminal before the flight departed at approximately 10am for Los Angeles Thursday morning."

Heavy thunderstorms pounded New York on Thursday night, delaying several flights. But many afternoon flights seemed to be unaffected, according to the airport's list of departures.