Several articles on this blog have shown how warm November and December so far have been for large portions of the eastern US. One of the consequences of this warmth is that winter wheat in Kansas and other parts of the Midwest has not reached dormancy yet.
This is a potential problem because the wheat needs to go into dormancy before it gets really cold or the wheat could be killed by the frigid temperatures, especially with no snow on the ground. You can read more about it in this AgWeb article from last week.
