Holy carp! It's -2°F up in Boston right now, and that's not even the overnight low. By comparison, it's a balmy 18°F here in Pittsburgh and 19°F in Minneapolis. What's up with that?

For those of you who like the NWS technical discussion: (emphasis mine)

Longer range (late Thursday through Tuesday)...

Record breaking cold along with dangerously cold wind chills remain on schedule for Thursday night and Friday...

Another round of arctic air arrives early in this period... with this airmass even colder than what we are experiencing this morning and likely colder than last Friday-Sat! Core of the arctic airmass moves over the region Thursday night and Friday... as polar vortex pentrates southeast as far as Gulf of ME/northwest portion of Georges Bank by 12z Friday (wow!). In the process of digging southeast... multiple polar vortices rotate through the region Thursday night and Friday. Thus... expect scattered snow showers and/or flurries to accompany these features. In addition... will likely see a period of ocean effect snow Thursday evening across the Cape and Nantucket. Although... appears to be short lived as winds quickly become west to northwest by midnight.

Compounding the severe cold will be dangerously cold wind chills of minus 25 to minus 45 Thursday night and Friday... in response to strong northwest winds of 25 to 35 miles per hour with gusts around 45 miles per hour. Given these wind speeds... as the event nears a Wind Advisory will likely be needed for at least a portion of the region Thursday night and Friday. In addition... will likely see wind chill warning values be met Thursday
night and early Friday. Would issue a wind chill watch... although with wind chill warnings and advisories already posted for this mornings cold... will address this next round of severe cold via special weather statement to minimize confusion.

Stay warm, kids!