Last February, I was on a cross-country trip with the kids, using SW. We were scheduled to leave Wednesday, connecting in Houston. The previous Saturday, they started predicting "Snowmageddon." I called SW, but since no advisory was issued, I couldn't change without paying the difference in fare (x3 was significant). I kept following all day Sunday, still no advisory. First thing Monday morning, I called again, was again told if I changed I would pay. I checked their website, and their social media. Their social media accounts were getting blasted by stranded passengers in the midwest and southwest, but still no advisory. I posted to their FB wall, pointing out that Delta and American had already issued advisories, were they planning to? I got a message back that they were, that I should call again. I called, was told no advisory, asked them to check with a supervisor as I had a message that they were issuing one. Agent came back on the line, told me they were, but it hadn't posted yet, but since I was on the phone, she'd go ahead and move me to a flight on Tuesday at no charge. I got 3 seats on the first flight out on Tuesday, and was told there were only a few seats left on that flight. We got to the airport at 530am. We were the only flight that took off on time that day, and by lunch, all flights were cancelled. Our airport was closed through Thursday night (small, Southern airport). The news was full of stories of stranded passengers. We were able to enjoy our trip, and even got an extra day out of it, because we were prepared to leave ahead of schedule and because I kept harrassing SWA. If you are prepared and vigilant (and maybe prepared to pay extra to change to another flight if absolutely necessary), you should be ok. Have a great trip!