Air travelers faced flight headaches across much of the East on Friday from the latest potent storm to move through the region.

Temperatures were expected to soar into the 50s and 60s as far north as New England before plunging to far-below freezing readings by Saturday. Some cities were forecast to see rain give way to snow or ice, though the large cities immediately along the coast were expected to get only rain.

The storm could disrupt flights at a number of busy airports, including the delay-prone airports serving the New York City and Philadelphia metro areas.

Most big airlines had enacted flexible rebooking polices for a number of airports, though the details varied significantly by carrier.

American’s covered more than a dozen airports, all in the mid-Atlantic and New England. The policies in place at each Southwest and JetBlue covered nearly 20 airports stretching from Maine to the Midwest to Tennessee, where Friday’s rain was forecast to give way to sleet and snow.

At Delta and United, the fee-waivers covered only flights at the greater New York City-area airports. However, by including their hubs at Newark (United) and LaGuardia (Delta) and JFK (Delta), the waivers covered connections from many other cities in the region. Frontier, Air Canada, Porter and WestJet were among other airlines that had waived change fees for certain airports in the eastern U.S.

Flight cancellations and delays already were creeping up Friday morning. More than 290 flights had been canceled nationwide and another 390 were delayed as of 8:40 a.m., according to flight-tracking service FlightAware.

So far, the hardest-hit airports were Newark Liberty (about 70 cancellations) and New York LaGuardia (about 45) as of 8:40 a.m. ET. North of the border, Toronto’s Pearson International Airport – a major hub for Air Canada – was suffering schedule disruptions amid poor weather there. About 10% of the entire day’s schedule had already been canceled there as of 8:10 a.m., according to FlightAware.

Travelers scheduled to fly on Friday should expect further disruptions in across the East Coast, Great Lakes and Ohio Valley as the storm moves through.