(CNN) -- A winter storm blasting the Northeast caused significant headaches for travelers on Friday, including long delays at several airports, according to the Federal Aviation Administration.
Flights destined for Newark Liberty International Airport in northern New Jersey were arriving more than four hours late on average, the FAA reported around 4 p.m. ET on its website.
Significant delays were reported elsewhere in the region as well, including about 2½ hours at both New York's LaGuardia airport and Boston's Logan airport.
The travel situation, however, did improve considerably over the course of the night.
By 9 p.m., for instance, most Northeast airports were experiencing only minimal delays. One exception then was LaGuardia, which still was experiencing 2½-hour backups on arriving flights, according to the FAA.
Even so, between United, Delta and American airlines alone, the bad weather caused at least 670 flight cancellations Friday in the Northeast corridor.
Some areas of Massachusetts could be under two feet of snow by the time the storm cleared the area Friday night, according to the National Weather Service.
The Northeast isn't the only area being hit by late wintry weather.
Blizzard warnings were posted through Saturday and in some cases into Sunday for parts of four Rockies and Plains states.
Parts of Colorado could see 10 to 15 inches of snow, according to the weather service.
Before it hit in full, the storm system had already caused travel issues.
United Airlines preemptively canceled 270 flights on Saturday and Southwest canceled another 125. Most of the cancellations impact Denver.