The economic impact could be more severe if the storm damages a port or a major manufacturing facility such as an oil refinery, Zandi noted.
The economy expanded at an annual rate of 2 percent in the July-September quarter. Zandi said he isn't changing his forecast for similar growth in the current October-December quarter of 1.9 percent. Economic activity in October and November might slow if factory output declines and some workers are laid off temporarily and seek unemployment benefits. But the economy could strengthen in December as companies rebound.
Here's how the storm has begun to affect key areas of the economy:
Flights in the Northeast are all but stopped for at least two days. Airlines have canceled nearly 12,500 flights for Monday and Tuesday from Washington to Boston. The disruptions spread across the nation and overseas, stranding passengers from Hong Kong to Europe.
Total airline cancellations have already surpassed those from Hurricane Irene last year and are on par with the 14,000 that were scrapped due to the snowstorm that pounded the East Coast early last year. The Airports Council International, a trade group, said that even if the storm damage turns out to be minor, it could be a week before operations are back to normal at major East Coast airports.