Among other things, the declaration [2] means you can't park on a snow-emergency route, but otherwise you can use a cone, chair, fan, toilet or stuffed animal to save a space on the street for up to 48 hours after the snow emergency officially ends.
Use this city mapping system [3] to find out which of your local roads double as snow emergency routes and where you can park at a discount (with a resident parking sticker on your car).