The long range potential of the GFS is salivating. Just look at the split flow, active southern stream and blocking over the top. You have REAL artic air dumping into the country straight out of Siberia through the entire month of January. Get the streams to merge on any of these chances and someone on the east coast is getting smoked. An elongated PV could lead to our southern friends getting hit instead. But the potential on these recent runs is the best I have seen since since 2009/10.