This is a really unusual weather situation, according to the National Weather Service: Three low pressure systems in line over the entirety of North America. NASA Goddard describes them as "three atmospheric dragons." They do look like dragons! It must be a Game of Thrones' marketing ploy.
There are three low pressure systems around the U.S. and they resemble dragons on satellite imagery. NOAA's GOES-13 and GOES-15 satellite image from March 31 shows the low pressure systems in the eastern Pacific Ocean, over the nation's Heartland, and in the eastern Atlantic Ocean. All three lows have the signature comma shape that make them appear to be curled up dragons.
According to the National Weather Service, the low pressure area approaching the northwestern U.S. is expected to bring rainfall to the coast and areas of snow that stretch from western Washington state south toward the four corners region. The low in the middle of the country is located over Nebraska and dropping snow to the north and west of it. That same low is bringing rain from southern Minnesota south to eastern Texas. Meanwhile, the third low pressure system is bringing rain and snow to parts of New England.
Sadly, these dragons have teeth. They are bringing blizzards and mark the start of the tornado season (the first of which was spotted in Minnesota today).
You can see the original animated images by the Space Science and Engineering Center at the University of Wisconsin-Madison here.
Here's the full globe view posted at NASA Goddard's Flickr page: