Here it is, your handy three step guide:
Step 1. Get things going early. Say, by suggesting 4 days ahead of the snow that the storm will be a threat to "life & property"
Step 2. Name the storm. This step is essential; you can't fear what you can't name. By the way, I'm fully behind the currently recommended name: Make Winter Great Again.
Step 3. Actually panic. Basically, do this:
And there you go, you're all set for a DC weather event!