Continuity mistake: Hunter shows the military a sign which includes the word "castrophic" rather than catastrophic. Then after the kids question his loyalty he holds the sign up again, but this time the word is spelled correctly. (00:40:00 - 00:41:00)
Other mistake: The temperature is dropping and everyone is bundling up to stay warm, yet when talking to Melanie, we can see Pauline is still wearing her sandals.
Suggested correction: That's a choice by the character. I've seen many people wearing sandals throughout the winter.