Due to weather issues, I expected to have travel problems flying from JFK-DCA tonight. I bought a ticket on DL (normally a UA flier) and was surprised by the inconsistencies in terms of cancellation information. As I got on the Airtrain from Jamaica Station, I got the notice that my flight was delayed by 3 hours (from 8pm to 11pm)...so I decided to head to the Terminal. Upon arrival, I got an email alert that my flight had been cancelled. After asking several indifferent staff members, they finally pointed me to the "Kiosk Assistance" line, where the agent told me that the flight was showing that it was just delayed and I should check with the agents at the gate. I logged onto the Delta website on my phone while I was standing in the security line and proceeded to look at the screens upon getting towards the gate area, which continue to show that the flight was delayed. When I logged onto the Delta website on my laptop, it still showed that it was cancelled, so I went to the gate agent, who told me that the flight was just delayed from what her computers were showing. Two hours later, the same agent announced that the flight was cancelled. I realize that cancellation is fluid, but not sure why I would receive email alert that my flight is cancelled, but the gate agent and screens at the airport just showed that it would be delayed. I did get rebooked to a flight tomorrow, but was frustrated to have killed 3 hours at the airport when I didn't have to.