http://radar.weather.gov/Conus/full.php
http://www.weather.com/maps/maptype/...her_large.html
The radar echoes for this map are already quite impressive, as is the isobar gradient between the high over Montana and the Low over Texas. You can see how important the track of this storm is, simply by looking at how the echoes are lining up. Even 50 miles could mean the difference between a foot of snow and 4 inches.