Flights across America have been affected by the massive blizzard burying the Northeast this week, including those leaving from airports far from the worst of the storm. 

As of early Tuesday morning, more than 7,700 U.S. flights had already been canceled, according to tracking service FlightAware.com. Most were to or from cities in the storm's path, from Washington through New York to Boston. An additional 2,000 flights were delayed.

Cancelations and delays are expected to spill over into Wednesday, if not later.

Airlines cancel flights before storms arrive to prevent passengers from driving to the airport and getting stranded in the terminal. Airlines also want to avoid having their planes stuck at snowed-in airports.

Most major U.S. carriers said they would allow passengers ticketed to, from or through the Northeast through Tuesday or Wednesday to change their plans without getting hit by a reservation-changing fee, typically $200.

But stranded travelers could still have extra costs. When weather causes delays, airlines have no legal obligation to find a hotel room or provide meals for stranded travelers, "although they might do so as a courtesy," said George Hobica, founder of the travel website airfarewatchdog.com. He advised travelers to check the terms of the credit card they used to book the trip — some include coverage for hotels and meals when flights are canceled due to weather.

Forecasters from the National Weather Service had begun revising their forecasted snow totals down early Tuesday. Boston was expected to get the worst of the storm and receive 18 to 24 inches of snow. New York City was projected to receive between 10 and 20 inches, while Philadelphia was forecast to get approximately 6 inches. 

The blizzard in the Northeast was having ripple effects for travelers and airports across the country. According to FlightAware, 45 flights scheduled to depart Los Angeles International Airport were canceled Tuesday, many of them bound for New York, Newark, Philadelphia, or Boston. Atlanta's Hartsfield-Jackson Airport had 70 flights canceled Tuesday, while San Francisco International Airport had 39 flights scrubbed. 

Here's what some major airlines are reporting:

UNITED AIRLINES

Will not fly Tuesday from New York, Boston or Philadelphia. Spokeswoman Mary Ryan said the airline would limit operations at Newark, New Jersey, and New York's LaGuardia and Kennedy airports on Monday night and cancel all Tuesday flights at those airports.

Callers were also experiencing long times on hold because of the heavy volume.

AMERICAN AIRLINES

American, its US Airways subsidiary and their regional affiliates planned to suspend operations late Monday at LaGuardia, Kennedy, Newark, Boston and Philadelphia and run a "very limited" schedule in the Northeast on Tuesday, said spokeswoman Andrea Huguely.

DELTA AIR LINES

Has already canceled 960 flights scheduled for Tuesday and expects to shut down at Boston's Logan Airport and offer limited flights at LaGuardia and Kennedy airports, said spokesman Morgan Durrant.

Durrant said Delta might cancel some flights Wednesday morning.

SOUTHWEST

Has already canceled nearly 50 Wednesday flights, said spokesman Brad Hawkins.

The Associated Press contributed to this report.