While we all know this is not easy for anyone, the tight capacity and limited options can wreak havoc for days even when the weather improves. Airlines have very limited slack and changes cannot easily be made. So who loses? The traveler is always the number 1 loser in these events. Airlines grant "waivers" and "flexibility", but when you are going to a specific event on a certain day and you hold a non-refundable ticket, this flexibility does not mean much.
Here's an excerpt of one airline's policy:
Due to weather in the Eastern U.S., XYZ Airlines offers the following flexibility options to ticketed customers whose travel may be impacted by this event. Customers ticketed to travel , departing from the affected airports may change flights
On the following dates: February 16, 2015 - February 17, 2015
And your ticket was issued no later than: February 15, 2015
You may travel: February 16, 2015 - February 20, 2015
Original inventory required? No
Origin/Destination/Stopover Changes allowed? No
The ticket reissue charge will be waived for one ticket change.
To change travel dates, contact our Reservations personnel at 1-800-XXX-XXXX within the United States or Canada.
As you see from above, the flexibility offers the same dates that flights are cancelled (February 16 and 17), and only allows 3 additional days to make the trip. Problem #1, you may no longer have the need to travel. Problem #2, if you do travel, you have to compete with other passengers on what looks like already oversold flights in a very tight window. Problem #3, if you choose not to travel or cannot find seats, you will have to pay a penalty for using your ticket on a future flight.