Two runways were open and active by Thursday afternoon, and all runways were expected to open about 6:30 p.m.
A handful of flights went out and landed from cities such as Las Vegas and Phoenix that had good weather.
The storm that cut electricity across the South and grounded thousands of flights forced the cancellation of 906, or 74 percent, at Philadelphia, according to FlightView, a Boston-based flight-tracking website. A total of 1,226 flights had been scheduled here.
Nationwide, 7,608 flights, or 22.6 percent, were scrubbed Thursday. Hardest-hit were Atlanta, with 1,257 cancellations; Charlotte, N.C., with 1,204; New York LaGuardia, 875; Washington Reagan National, 800; and Newark Liberty, 796.
As of 4:30 p.m. Thursday, FlightView reported that 107 flights had been canceled for Friday in Philadelphia, or 12.8 percent.
Southwest Airlines said it expected to run a normal operation beginning with the first arriving flights in Philadelphia Friday. Southwest canceled all Philadelphia flights and nearly 800 across the Southwest and AirTran system Thursday.
"We expect the first scheduled arrivals to operate normally Friday and, from there, the system begins to right itself," said Southwest spokesman Brad Hawkins.
US Airways plans to operate most arrivals and departures Friday morning at its hubs in Philadelphia and Charlotte, "but this is subject to change based on weather conditions," said spokesman Davien Anderson. "We urge customers who have travel plans, or who are dropping off or picking up a loved one, to check their flight status at usairways.com or at aa.com if they are traveling on a flight operated by American Airlines," he said.
About 2,200 of US Airways' 3,000 daily flights were canceled Thursday.
"We continue to operate on a very limited basis at Philadelphia," Anderson wrote in an early-evening e-mail.
Based on the snow and wintry mix, US Airways, Philadelphia's dominant carrier, reduced operations more than 50 percent Thursday at Philadelphia, Washington Reagan, and New York LaGuardia. US Airways, now part of American Airlines Group Inc., canceled all flights in and out of Charlotte.