The jet stream keeps looping above northern Greenland, then collapsing down into the central Atlantic. This is happening because the North Atlantic is still too warm from last summer. When it collapses, it causes cold arctic air to mix with warmer air over the Atlantic, which then rotates in across eastern North America in the form of a blizzard with a storm structure like a hurricane, although hopefully without the high speed winds. To read the media story about the storm–without the explanation of why, of course–click here.