huge trough of cold air comming down out of canada. let me show you the timeline of where that 32* line is. Green/blue is precip, obviously. notice how it starts out with the 32* line just to our north, then slowly creeps south into the precip by hour 126. (keep in mind that it can snow with temps as high as 36*, and probably will, because the ground is so fucking frozen lol.)
Hour 114:
http://lh6.ggpht.com/_zt1IrYTCrOo/TP7zd2TksaI/AAAAAAAABK8/NE5X2KBW5yA/s800/3.gif.jpg
120:
http://lh3.ggpht.com/_zt1IrYTCrOo/TP7oJV0_ntI/AAAAAAAABKk/xZkAPtL4fKo/s800/12zgfs850mbTSLPp06120.gif.jpg
126:
http://lh3.ggpht.com/_zt1IrYTCrOo/TP7y0zxVZwI/AAAAAAAABKs/7VQvoRp2jNo/s800/1.gif.jpg
hour 132:
http://lh4.ggpht.com/_zt1IrYTCrOo/TP7y1a9guaI/AAAAAAAABKw/lJasHqRhFbE/s800/2.gif.jpg