I don't care what others say, until the southern jet feature is inside the North American RAOB network, wild swings occur. During the Dec 2009 snowstorm, there was a RAOB site (New Orleans?) that was launched late and they didn't get in for the 00z GFS. The result was a dry looking 00z GFS/GEFS that freaked a lot of people out. Thankfully someone here caught it in the NCEP model diagnostic disco (I think it was either you or @WxUSAF). Color us shocked when the 12z GGS/GEFS snapped back to a big storm.